Customer lifetime value for SaaS founders. Plug in margin math, see the number — plus the breakdown behind it. All local.
Gross-profit model: (price − cost) × purchases − acquisition cost. Calculates live.
Net lifetime value after acquisition cost.
Rules of thumb: LTV:CAC ≥ 3 is healthy, < 1 means you lose money on every customer. If cost ≥ price, margin is zero or negative — fix pricing before scaling acquisition.
Every keystroke recalculates — there is no submit button. The four fields map directly onto the formula in §02, and the result panel narrates what the number means.
1 · Enter price and cost per sale. Price is revenue per purchase before costs; cost per sale bundles COGS, delivery and fees for one purchase. Price must be over zero, cost cannot be negative — and if cost reaches price, the tool raises its warning banner because margin is zero or negative and no volume of customers can fix that.
2 · Enter lifetime purchases and CAC. Lifetime purchases is a whole number of 1 or more — how many times a customer buys before churning. CAC is optional and defaults to zero when blank. Unsure about purchases? Start with the Load example button (price 99, cost 22.50, 8 purchases, CAC 40) and adjust from a working baseline.
3 · Read the six result rows. Gross profit per sale, total lifetime gross, minus CAC, gross margin, the LTV:CAC ratio, and sales needed to pay back CAC. Each row isolates one lever: margin problems show in row one, retention problems in row two, acquisition problems in rows five and six.
4 · Act on the verdict. Healthy means the ratio clears 3× — scale carefully. Workable-but-thin (1–3×) means push retention or trim CAC before spending. Below 1×, or a negative CLV, means stop acquiring and fix unit economics first. The verdict box states which case you are in, in plain language.
This tool uses a gross-profit model: CLV = (average price − cost per sale) × lifetime purchases − CAC, all in USD. It suits any repeat-purchase business — SaaS seats, coffee subscriptions, replacement parts. Each output row is one step of that arithmetic, verified against the page logic in Sep 2026:
| Output | Definition | Example value |
|---|---|---|
| Gross profit / sale | Price minus cost per sale | $76.50 |
| Total gross (lifetime) | Gross profit × lifetime purchases | $612.00 |
| CLV | Lifetime gross minus CAC | $572.00 |
| Gross margin | Gross profit ÷ price | 77.3% |
| LTV : CAC | Net CLV ÷ CAC (∞ when CAC is 0) | 14.3× |
| Payback | CAC ÷ gross profit per sale, rounded up | 1 sale |
Worked example — the Load example preset. Price $99.00, cost $22.50, 8 lifetime purchases, CAC $40.00: gross profit per sale is $76.50, lifetime gross $612.00, CLV $572.00, margin 77.3%, ratio 14.3×, payback 1 sale. The verdict reads Healthy — 14.3× clears the 3× bar comfortably.
The subscription contrast. Pure-subscription teams usually write LTV as ARPA × gross margin ÷ churn rate instead of counting purchases. The two forms agree when margin and churn are steady — expected renewals ≈ 1 ÷ churn, so 5% monthly churn implies about 20 purchases. Use whichever form matches the data you actually have.
The 3× bar, honestly labeled. LTV:CAC ≥ 3 as healthy and < 1 as losing money is a widely cited SaaS rule of thumb — venture investor Tomasz Tunguz recommends ramping sales and marketing spend once the ratio exceeds 3× — not a law of nature. Note this tool's ratio divides net CLV (already minus CAC) by CAC, which is one notch stricter than the classic gross-LTV version: clearing 3× here means clearing it anywhere. Early-stage founders should weight the payback row heaviest, since it needs no long-dated lifetime assumptions.
Known limits. No discounting of future cash, no retention curve (every purchase counts equally), no expansion revenue, and CAC is a single blended number rather than a channel mix. Treat the output as a directional unit-economics check, not a valuation input.
The distinctions that confuse people, answered against this tool's actual model (verified Sep 2026).
CLV (customer lifetime value) and LTV (lifetime value) name the same idea — total value one customer delivers. CAC (customer acquisition cost) is its cost counterpart: blended sales and marketing spend to win one customer. This tool computes net CLV as (price − cost) × purchases − CAC, then shows the LTV:CAC ratio beside it, so value and cost stay in one frame. Confusion usually comes from vendors mixing gross and net definitions — here CLV is always net of CAC.
For subscriptions, expected renewals ≈ 1 ÷ churn rate: 5% monthly churn implies roughly 20 purchases, 2% implies about 50. For transactional businesses, use cohort history — what fraction of last year's buyers bought again, and how often. With no history at all, model two or three scenarios (pessimistic, base, optimistic) rather than trusting one number. And if you are pre-product-market fit, prefer the payback row: it needs no lifetime assumptions.
Both, with one caveat. The (price − cost) × purchases − CAC model fits any repeat-purchase business, from SaaS seats to consumables. Pure subscription teams often prefer ARPA × gross margin ÷ churn, which needs churn data this tool never asks for. If you have stable churn, use that form; if you think in purchases and per-sale costs, you are in the right place. One-off sales need no CLV math — margin per sale is the whole story.
This tool divides net CLV (after subtracting CAC) by CAC, while the textbook 3× heuristic divides gross lifetime value by CAC. The tool's version is stricter — a 3.0× here would read higher in gross terms — so treat its bands as conservative. The direction never flips: a ratio that looks healthy here looks healthy anywhere, and a sub-1× ratio means acquisition destroys value under either definition.
You left CAC blank, so it defaults to zero and there is nothing to divide by. The ∞ label means unit economics before acquisition are positive — every sale contributes margin. It is a starting point, not a victory: add your real blended CAC (ad spend plus sales cost, divided by new customers) to see the true ratio. Organic-only businesses can keep a genuine zero, but most should fill the field in.
Each customer costs more than they return, so every dollar of growth spending deepens the hole. Work the levers in order: raise price or cut cost per sale (margin first, it compounds across every purchase), extend lifetime through onboarding and retention, then lower CAC by fixing conversion before volume. Re-run the numbers after each change — the tool's verdict flips to workable the moment the math turns, and only then should you scale acquisition.
All figures above were recomputed from this page's own JavaScript in September 2026: the Load example preset (99 / 22.50 / 8 / 40) yields $76.50 gross profit, $612.00 lifetime gross, $572.00 CLV, 77.3% margin, a 14.3× ratio and 1-sale payback, and the verdict bands (losing / below 1× / 1–3× / healthy at 3×+) match the code paths. Everything runs client-side — your pricing never leaves the browser and there is nothing to sign up for. The LTV:CAC 3× bar is presented as an industry rule of thumb with a named source, not a guarantee; your payback period and margin quality matter as much as the headline ratio. Limits to respect: no time discounting, no retention curves, no expansion revenue — directionally right, not audit-grade.