How much is my online tool or web app worth?

Use the SDE multiple framework. Calculate monthly SDE (subscription MRR plus usage-based MRR, minus hosting and API costs, minus contractor costs and software subscriptions, plus owner salary add-back). Then apply the baseline multiple for your SDE tier: under $500/month at 25-38x; $500-$2,000/month at 33-48x; $2,000-$5,000/month at 40-55x; $5,000+/month at 45-60x. A tool generating $3,000/month SDE at a 44x multiple equals $132,000. The three biggest levers that determine where in that range your tool falls are MRR composition (90%+ subscription MRR is premium), monthly churn rate (under 2% earns a premium; above 4% earns a significant discount), and LTD overhang (above 30% LTD users earns a 10-20% discount regardless of other metrics). If your LTD users represent 35% of your active base and your core feature relies on OpenAI's API, expect a 20-30% discount from the baseline multiple.

How do I calculate SDE for an online tool or web app?

Monthly tool SDE equals subscription MRR plus usage-based MRR, minus all cloud and hosting costs, minus third-party API costs (OpenAI, Stripe, Twilio, SendGrid), minus contractor costs for support and code maintenance, minus any software subscriptions, plus the owner's personal salary add-back. The unique calculation steps for tools compared to other business types: (1) calculate infrastructure margin first, separate out all variable hosting and API costs and verify that the margin is stable, not eroding as usage scales; (2) exclude LTD revenue entirely, it is non-recurring and was collected in a prior period; only the ongoing per-user infrastructure obligation remains; (3) add back the market-rate cost of replacing the owner's technical time, if the owner spends 6 hours per week on code updates and a contractor would charge $2,000/month for that work, $2,000 is the add-back. Verify from the payment processor export and infrastructure provider invoices for the trailing 12 months.

How does MRR composition affect a tool or app valuation?

MRR composition, the breakdown of recurring revenue into subscription MRR, usage-based MRR, one-time license fees, and LTD revenue, is the primary multiple driver for tool acquisitions because different revenue types have very different predictability and risk profiles for the acquirer. Pure subscription MRR is the highest-quality type: contracted, predictable, and non-decaying without active re-selling. Usage-based MRR is variable but signals strong product engagement, users consuming more as they get more value. One-time license fees and LTD revenue are non-recurring: once collected, they generate no future income but may create ongoing obligations (LTD overhang). A tool where 90% or more of revenue is subscription MRR with under 2% monthly churn trades at the top of its SDE tier multiple range. A tool where 50% of revenue is one-time licenses with the remainder subscription may trade 20-30% below a subscription-only comparable, because the license cohort decays without re-selling and provides no forward revenue visibility. During due diligence, always request a full revenue-type breakdown from the payment processor, not just a single MRR number.

What is the biggest due diligence risk when valuing a tool or web app?

The most dangerous combination in tool acquisitions is undisclosed LTD overhang paired with eroding infrastructure margin: thousands of lifetime deal users creating permanent infrastructure cost obligations while per-user cloud or API costs increase with usage, causing SDE to compress further after close. This combination often appears when a tool ran a large AppSumo campaign, onboarded thousands of LTD users, and subsequently integrated an AI API whose per-request costs scale with usage. The seller's reported SDE may look healthy, but the buyer inherits a growing cost burden with no revenue to offset it. The second biggest risk is a codebase bus factor of 1, the entire architecture, deployment process, and maintenance knowledge residing in the sole founder-developer with no documentation. Even clean financials cannot compensate for a non-technical buyer discovering that a server restart or dependency update requires the seller's involvement. During due diligence: verify the LTD user count and per-user infrastructure cost; review the trailing 12-month infrastructure margin trend; request deployment runbooks and a README; and calculate a post-acquisition SDE scenario that includes full LTD infrastructure costs before making an offer.

How to value an online tool or web app

Online tools and web apps are valued as a multiple of monthly SDE, but tool valuations have unique risk factors absent from every other business type: LTD overhang, infrastructure margin erosion, MRR composition, API dependency, and codebase bus factor. This 8-step guide covers how to calculate true SDE, assess the factors that compress or expand the multiple, and arrive at a defensible bid range for any productivity tool, browser extension, API utility, or micro-SaaS product.

Calculate trailing 12-month (TTM) MRR

Start by separating revenue by type: subscription MRR (flat monthly or annual recurring charges), usage-based MRR (variable charges tied to API calls, seats, or data processed), one-time license fees, and lifetime deal (LTD) payments. Only subscription MRR and usage-based MRR transfer value to a buyer as recurring revenue, one-time license fees and LTD payments are non-recurring and must be excluded from the SDE base. To verify MRR, request read-only access to the payment processor (Stripe, Paddle, Lemon Squeezy) and export a month-by-month MRR breakdown for the trailing 12 months. Reconcile the export against the seller's stated MRR to identify discrepancies. Pay attention to annual subscription payments that inflate a single month's MRR but represent 12 months of revenue, normalize these to monthly equivalents for an accurate TTM MRR figure. If the tool has LTD users from AppSumo, StackSocial, or a direct campaign, request the total LTD user count and the date of the last LTD campaign, because that history determines the size of the LTD overhang the buyer will inherit.

Compute infrastructure margin

Before calculating SDE, isolate the infrastructure margin, the gross margin remaining after deducting all variable hosting, compute, storage, API, and cloud costs from MRR. This is the most critical pre-SDE step for tool valuations because infrastructure costs vary enormously by product type: a static calculator tool may have a 97% infrastructure margin, while an AI-powered tool making metered OpenAI or Google Cloud Vision API calls per user action may retain only 55-65%. Request a monthly breakdown of all cloud infrastructure costs for the trailing 12 months: hosting (AWS EC2, GCP, DigitalOcean, Hetzner), storage (S3, Cloudflare R2), CDN, database (PlanetScale, Supabase, Neon), and all third-party API costs by provider. Calculate infrastructure cost as a percentage of MRR each month and plot the trend. If infrastructure costs are growing faster than MRR, the per-user cost is scaling up as the user base grows, the SDE will compress after acquisition. This is a warning sign that the seller's reported SDE overstates what the buyer will actually earn.

Compute true SDE

Monthly SDE equals subscription MRR plus usage-based MRR, minus infrastructure costs (from Step 2), minus contractor costs for support and development maintenance, minus software subscriptions and platform tool costs, minus any paid marketing spend, plus the owner's personal salary and any personal expenses run through the business. LTD revenue is excluded entirely, it was collected in a prior period and creates an ongoing cost obligation (LTD overhang) rather than future income. The most common SDE calculation mistakes for tool acquisitions are: (1) including LTD revenue in MRR without accounting for the ongoing infrastructure cost those users impose; (2) not deducting infrastructure costs accurately, sellers sometimes bundle hosting, API, and CDN into a single line that understates the true variable cost; (3) not adding back the market-rate cost of replacing the owner's time, if the owner works 8 hours per week on support and code updates and a hired developer would cost $3,000/month for that work, that $3,000 is the add-back. Verify SDE from the payment processor export, reconciled against the bank statement and infrastructure provider invoices for the trailing 12 months.

Apply baseline multiple by SDE tier

Online tools and web apps trade at different baseline multiples depending on the monthly SDE level. As of 2026, baseline ranges: micro-tools generating under $500/month SDE typically trade at 25-38x monthly SDE; small tools generating $500-$2,000/month SDE at 33-48x; established tools generating $2,000-$5,000/month SDE at 40-55x; larger tools generating over $5,000/month SDE at 45-60x. These ranges assume verified subscription MRR via payment processor export, monthly churn under 2%, a disclosed LTD user count, and no undisclosed critical API dependency. Tools below these thresholds on any factor will trade at the lower end of the range or below it. Never calculate the multiple from the asking price, calculate it yourself from verified SDE. A tool listed at $180,000 with claimed $4,500/month SDE is listed at 40x; if verified SDE is actually $3,000/month after properly accounting for infrastructure costs and LTD overhang, the asking multiple is 60x, significantly above market and justifying a meaningful counter.

Assess MRR composition and churn rate

MRR composition is the primary multiple driver for tool acquisitions. A tool where 90% or more of revenue is pure subscription MRR with under 2% monthly churn commands the upper end of the multiple range. A tool with 50% one-time license revenue and 50% subscription MRR, where the license cohort generates no future revenue, may trade 20-30% below a subscription-only comparable. Assess MRR composition by requesting a full revenue breakdown by type from the payment processor and calculating the subscription percentage. For churn, request monthly cohort data for the trailing 12 months: the percentage of subscription users who cancelled in each month. A single churn figure is unreliable, verify that churn is consistent across months and not artificially suppressed by a recent LTD campaign or annual plan prepayments that have yet to renew. Churn rate multiple adjustments: under 1% monthly churn earns a 15-25% premium above baseline; 1-2% earns the baseline; 2-4% earns a 0-15% discount; above 4% justifies a 15-30% discount or pass. Also check the monthly active rate (MAR), the percentage of registered users who take at least one meaningful action each month. A tool with 95% retention but 30% MAR has a large cohort of disengaged subscribers who are likely to cancel once they audit their subscriptions.

Evaluate LTD overhang

LTD overhang, the cumulative ongoing infrastructure and support cost imposed by all outstanding lifetime deal users with no recurring revenue to offset it, is one of the most commonly undisclosed valuation risks in tool acquisitions. Request the total LTD user count from the product database, broken down by LTD plan tier if multiple tiers were sold. Calculate the per-user monthly infrastructure cost (total monthly infrastructure cost divided by total active users, including LTD users) to determine the true cost the LTD cohort imposes. Apply these discount benchmarks: under 15% of active users on LTD plans has minimal multiple impact, since the cohort is manageable; 15-30% LTD users justifies a 5-10% multiple discount as the buyer reduces SDE to reflect true infrastructure costs; above 30% LTD users justifies a 10-20% multiple discount and signals that the recurring subscription model may have struggled to sustain traction. A tool where the top three LTD tiers each included unlimited feature access also creates a hidden support burden, heavy-use LTD users are often disproportionate consumers of customer support time relative to paying subscribers. Build a realistic post-acquisition SDE by: starting with verified MRR, subtracting full infrastructure costs including LTD-proportional share, and applying the resulting adjusted SDE to the multiple rather than the seller's stated figure.

Assess API dependency and platform risk

API dependency is a tool-specific valuation risk with no equivalent in content sites or service businesses. If a tool's core functionality relies on a single third-party API, OpenAI for its AI features, Twilio for SMS, Google Maps for mapping, a pricing change, rate limit reduction, or terms-of-service update from that provider can materially impair the product's value or require significant redevelopment. Apply these adjustments: no critical API dependency for core functionality earns the full multiple range for the tier; non-critical API usage (Stripe for payments, SendGrid for transactional email) has no material multiple impact; a critical single API where the product's core value proposition depends on one provider justifies a 10-20% discount; tools distributed exclusively through a marketplace (Chrome Web Store for browser extensions, Shopify App Store for Shopify apps) are subject to store policy changes that could delist or restrict the product and justify a 5-15% discount. During due diligence, request a list of all API integrations, their monthly cost, their rate limits, and whether the provider's terms allow commercial resale of the output. For AI API dependencies, review the pricing history of the provider's API over the trailing 24 months, if per-token costs have increased significantly, model the SDE impact of another 30-50% increase.

Evaluate codebase bus factor and arrive at bid range

The bus factor, the minimum number of developers who must become unavailable before the codebase can no longer be maintained, is the final valuation factor unique to tool acquisitions. A bus factor of 1 (the sole founder has all technical knowledge) does not disqualify a deal, but it creates significant post-acquisition operational risk for non-technical buyers: a failing server, a dependency conflict, or an expired API key may require the original developer's involvement to resolve. To assess bus factor during due diligence: review whether there is a deployment runbook covering how to push updates; whether there is a README covering local development setup, environment variables, and architecture; and whether a second developer can independently spin up and deploy the application without the seller's help. A tool with bus factor 1 and no runbooks warrants a 10-20% multiple discount or a requirement for a longer 60-90 day seller support commitment with a deferred payment portion tied to knowledge transfer milestones. After completing steps 1-7, build three scenarios. Conservative: apply maximum discounts for high LTD overhang, critical API dependency, high churn, or bus factor 1 with no documentation, this is the floor. Midpoint: apply the baseline multiple with the specific adjustments identified. Premium: for tools with 90%+ subscription MRR, under 2% churn, no LTD exposure, no critical API dependency, and a documented codebase, apply the top of the tier range. Structure the offer with a deferred payment or earnout portion for any tools with material LTD or API risk.

LTD overhang is the most commonly overlooked risk in tool acquisitions

Buyers consistently verify MRR, churn, and API dependencies, but many skip quantifying the true cost of outstanding lifetime deal users. A tool with 2,500 LTD users on AppSumo plans paying $0/month, each consuming $0.60/month in compute and storage, represents $1,500/month in unavoidable infrastructure cost with zero MRR to offset it. That burden compounds if the tool also relies on a metered AI API: as LTD users engage more heavily, API costs scale without any revenue increase. Before finalizing any tool valuation, request a full user-type breakdown from the product database, calculate the per-user infrastructure cost for the LTD cohort, and recompute SDE after accounting for the true LTD burden. The adjusted SDE, not the seller's stated figure, is what the multiple should be applied to.

Tool and web app valuation metrics cheat sheet

Metric	Good	Caution	Red Flag
MRR Composition	90%+ subscription MRR	50-90% subscription	Below 50% subscription (heavy license/LTD)
Monthly Churn Rate	Under 1%	1-3%	Above 4% (unsustainable)
LTD User %	Under 15% of active users	15-30%	Above 30% (significant overhang)
Infrastructure Margin	Above 80% and stable	60-80% or declining	Below 60% or eroding with scale
API Dependency	None critical; supporting APIs only	Single non-critical API	Core feature locked to one metered API
Monthly Active Rate	Above 60% of subscribers	30-60%	Below 30% (leading churn indicator)
Codebase Bus Factor	Documented; second dev can deploy	Partial docs; seller support needed	Bus factor 1, no runbooks
Monthly SDE Multiple	40-55x (premium tier)	30-42x (baseline tier)	Below 28x (distressed)

Frequently asked questions

How much is my online tool or web app worth?: Use the SDE multiple framework. Calculate monthly SDE (subscription MRR plus usage-based MRR, minus hosting and API costs, minus contractor costs and software subscriptions, plus owner salary add-back). Then apply the baseline multiple for your SDE tier: under $500/month at 25-38x; $500-$2,000/month at 33-48x; $2,000-$5,000/month at 40-55x; $5,000+/month at 45-60x. A tool generating $3,000/month SDE at a 44x multiple equals $132,000. The three biggest levers that determine where in that range your tool falls are MRR composition (90%+ subscription MRR is premium), monthly churn rate (under 2% earns a premium; above 4% earns a significant discount), and LTD overhang (above 30% LTD users earns a 10-20% discount regardless of other metrics). If your LTD users represent 35% of your active base and your core feature relies on OpenAI's API, expect a 20-30% discount from the baseline multiple.
How do I calculate SDE for an online tool or web app?: Monthly tool SDE equals subscription MRR plus usage-based MRR, minus all cloud and hosting costs, minus third-party API costs (OpenAI, Stripe, Twilio, SendGrid), minus contractor costs for support and code maintenance, minus any software subscriptions, plus the owner's personal salary add-back. The unique calculation steps for tools compared to other business types: (1) calculate infrastructure margin first, separate out all variable hosting and API costs and verify that the margin is stable, not eroding as usage scales; (2) exclude LTD revenue entirely, it is non-recurring and was collected in a prior period; only the ongoing per-user infrastructure obligation remains; (3) add back the market-rate cost of replacing the owner's technical time, if the owner spends 6 hours per week on code updates and a contractor would charge $2,000/month for that work, $2,000 is the add-back. Verify from the payment processor export and infrastructure provider invoices for the trailing 12 months.
How does MRR composition affect a tool or app valuation?: MRR composition, the breakdown of recurring revenue into subscription MRR, usage-based MRR, one-time license fees, and LTD revenue, is the primary multiple driver for tool acquisitions because different revenue types have very different predictability and risk profiles for the acquirer. Pure subscription MRR is the highest-quality type: contracted, predictable, and non-decaying without active re-selling. Usage-based MRR is variable but signals strong product engagement, users consuming more as they get more value. One-time license fees and LTD revenue are non-recurring: once collected, they generate no future income but may create ongoing obligations (LTD overhang). A tool where 90% or more of revenue is subscription MRR with under 2% monthly churn trades at the top of its SDE tier multiple range. A tool where 50% of revenue is one-time licenses with the remainder subscription may trade 20-30% below a subscription-only comparable, because the license cohort decays without re-selling and provides no forward revenue visibility. During due diligence, always request a full revenue-type breakdown from the payment processor, not just a single MRR number.
What is the biggest due diligence risk when valuing a tool or web app?: The most dangerous combination in tool acquisitions is undisclosed LTD overhang paired with eroding infrastructure margin: thousands of lifetime deal users creating permanent infrastructure cost obligations while per-user cloud or API costs increase with usage, causing SDE to compress further after close. This combination often appears when a tool ran a large AppSumo campaign, onboarded thousands of LTD users, and subsequently integrated an AI API whose per-request costs scale with usage. The seller's reported SDE may look healthy, but the buyer inherits a growing cost burden with no revenue to offset it. The second biggest risk is a codebase bus factor of 1, the entire architecture, deployment process, and maintenance knowledge residing in the sole founder-developer with no documentation. Even clean financials cannot compensate for a non-technical buyer discovering that a server restart or dependency update requires the seller's involvement. During due diligence: verify the LTD user count and per-user infrastructure cost; review the trailing 12-month infrastructure margin trend; request deployment runbooks and a README; and calculate a post-acquisition SDE scenario that includes full LTD infrastructure costs before making an offer.

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