Unit Economics Calculator
The formula
What the unit economics tells you
The per-customer balance sheet: lifetime gross profit versus acquisition cost. Every SaaS growth decision is downstream of this ratio.
Calculation: LTV = ARPU × margin ÷ churn; ratio = LTV ÷ CAC; payback = CAC ÷ (ARPU × margin). Enter your inputs and every substitution is shown below the result.
Reading the result
Read LTV:CAC and payback together — a 5× ratio with an 18-month payback still starves a fast-growing company.
Rules of thumb: SaaS benchmarks: LTV:CAC ≥ 3; payback <12 months self-serve, <18 sales-led
Limitations and best practice
Churn carries the whole calculation: use revenue churn with cohort evidence, not an optimistic annual logo average.
This calculator gives an estimate based on standard formulas; it is not professional financial, medical, legal or engineering advice. Verify anything you plan to act on with a qualified professional and your own records.
Frequently asked questions
Minimum acceptable ratio?
Should LTV be discounted?
Source & methodology
Bessemer / a16z unit-economics conventions.
Unit Economics: the number, the method and the caveats
This page was written for one job: turning your own inputs into a defensible figure, with the working shown. There are plenty of pages about Unit Economics; almost none of them show the working. This one does: the formula, every input, a fully computed example, and a sensitivity analysis calculated live from this engine’s own defaults.
People rarely disagree about arithmetic; they disagree about assumptions that were never written down. Printing the substitution and the sensitivity ranking removes that category of disagreement for Unit Economics.
Most confusion about Unit Economics comes from mixing up the input you control with the input you merely observe. The formula treats them identically, but your decisions should not: one deserves measurement, the other deserves a defensible estimate.
What makes a calculation page trustworthy is that its copy is derived from its own arithmetic: here LTV : CAC ratio = 12.78 ×, recomputed every time a field changes, and the sensitivity section ranks the inputs that move the result — Customer acquisition cost first, at ≈11.1 % of the headline for a ten-percent error either way in that input. Read the sections in order and you will be able to reproduce every figure by hand.
Every input in Unit Economics, and what it does to the answer
One formula, published in full: LTV = ARPU × margin ÷ churn; ratio = LTV ÷ CAC; payback = CAC ÷ (ARPU × margin). Anything you can read, you can reproduce in a spreadsheet, and that reproducibility is the whole point of printing it rather than hiding it behind a button.
Monthly revenue per customer ($) (example value 245) is a measured number in the unit named by the label; the formula does not convert for you. This input feeds the formula directly; a defensible figure here is worth more than false precision anywhere else.
Gross margin (%) (example value 84) is a quantity rather than a category — precision here is cheap and worth having. Enter it exactly as your document states it — quoted annual, monthly and effective rates are three different numbers.
Customer acquisition cost ($) (example value 805) is a measured number in the unit named by the label; the formula does not convert for you. Keep every money input in the same currency; mixing systems quietly corrupts the comparison.
Monthly revenue churn (%) (example value 2) is a plain measured quantity — the unit shown in the label is the unit the formula expects. Check the convention first: if the source says “6.5 % per year”, type 6.5 and let the formula do the rest.
Unit Economics on the example inputs: the complete substitution
Abstract formulas are hard to trust, so here is the complete substitution using the default inputs, written the way an examiner would want it. Starting figures: Monthly revenue per customer ($), Gross margin (%), Customer acquisition cost ($), Monthly revenue churn (%). Run to the end, the LTV : CAC ratio resolves to 12.78 × — Healthy unit economics on the bands this tool uses.
- Monthly contribution = $245 × 84% = $205.80
- LTV = ÷ churn 2% = $10,290; payback = 805 ÷ 205.80 = 3.9 months
Customer lifetime — 50.0 months. This is the number experienced users quote when the headline alone would mislead.
Lifetime value (gross-profit basis) — $10,290. This is the number experienced users quote when the headline alone would mislead.
CAC payback period — 3.9 months. Read next to the headline, this is the figure that shows the shape of the trade-off.
Max CAC that still gives a 3× ratio — $3,430. This is the number experienced users quote when the headline alone would mislead.
Re-running with your own figures is instant; re-running by hand once is the best way to know the tool is telling you the truth.
Scenario table: Unit Economics at ±10 % and ±20 % of the key input
The honest version of any estimate is a corridor, and this one is cheap to produce: Unit Economics was recomputed at 5 points along the dominant input, with every other field left untouched.
| Customer acquisition cost setting | LTV : CAC ratio |
|---|---|
| 80 % of the example value | 15.98 × |
| 90 % of the example value | 14.20 × |
| example inputs | 12.78 × |
| 110 % of the example value | 11.62 × |
| 120 % of the example value | 10.65 × |
Across 5 settings of Customer acquisition cost, the result spans 10.65 × to 15.98 ×. A decision that only works at one row of this table is a decision waiting for an input to move. Reproduce it in the form above by editing Customer acquisition cost alone; the substitution steps will follow your figures exactly.
Sensitivity: which inputs change Unit Economics the most
This list was computed for this specific engine just now: each numeric input was nudged ±10 % while every other field held its example value, and the LTV : CAC ratio was recalculated from scratch. For Unit Economics the ranking is measured rather than guessed, and it belongs to these defaults: shift the starting point and the order can shift with it.
- Customer acquisition cost +10 % → Unit Economics = 11.62 × · −10 % → 14.20 × (the LTV : CAC ratio shifts ≈11.1 %)
- Nudge Monthly revenue churn by ±10 % and Unit Economics lands between 11.62 × and 14.20 × (sensitivity ≈11.1 %)
- Monthly revenue per customer +10 % → Unit Economics = 14.06 × · −10 % → 11.50 × (the LTV : CAC ratio shifts ≈10.0 %)
- Nudge Gross margin by ±10 % and Unit Economics lands between 11.50 × and 14.06 × (sensitivity ≈10.0 %)
Customer acquisition cost is the dominant lever here: ten percent either way moves the result by about 11.1 %, from 11.62 × to 14.20 ×. Measure that input from a document rather than from memory, and Monthly revenue churn is effectively tied with it (≈11.1 % for the same nudge), so verify the pair together. The remaining fields can sit at safe defaults without materially changing the answer — knowing which is which is what separates a careful calculation from an anxious one.
What a Unit Economics of 12.78 × means in practice
Nobody acts on a bare figure — they act on a figure with a comparison attached. On the example inputs the band reads “Healthy unit economics”; your own figures place you on a different rung of the same ladder. How much of that band is luck? On Customer acquisition cost alone ten percent either way covers 11.62 × to 14.20 ×. The practical reading rules: compare against your own history before comparing against other people; treat band boundaries as zones, not walls — one point on the wrong side of a threshold rarely changes a real outcome; and when a companion output contradicts the headline, believe the pair.
The comparison worth making is not with somebody else’s Unit Economics but with the version of your own situation measured last quarter — same formula, same conventions, different inputs.
Common mistakes with Unit Economics (and the fix)
Churn carries the whole calculation: use revenue churn with cohort evidence, not an optimistic annual logo average. This calculator gives an estimate based on standard formulas; it is not professional financial, medical, legal or engineering advice. Verify anything you plan to act on with a qualified professional and your own records.
Treating the example inputs as a recommendation. They are a demonstration of the mechanism — a decision-grade Unit Economics begins the moment your own figures replace them.
This model has its own particular trap: Customer acquisition cost carries ≈11.1 % of the response per ten percent of error, so effort spent elsewhere is largely decorative.
Another is comparing across contexts: a Unit Economics computed with one set of conventions should never be lined up against a figure computed with another. Check the inputs behind both before ranking them.
Before you trust your Unit Economics: a short checklist
- State, in one sentence, which convention each rate, unit or period in the form is using.
- Recompute once with the dominant input deliberately set low, and see whether the decision changes.
- Re-verify Customer acquisition cost against a source document — ten percent of error there moves the headline by ≈11.1 %.
- Note the date and the inputs beside the number so the figure can be audited later.
- Compare the result with one independent method or published benchmark.
- Repeat the ±10 % test on the inputs that matter and see whether the decision — not just the number — still holds.
How to use the Unit Economics tool properly
Using a calculator well sounds trivial, but the difference between a decision-grade figure and a throwaway one lives entirely in the routine. The routine for Unit Economics takes a minute to learn and applies to every input above.
Step 1 — gather before you type. Unit Economics depends on monthly revenue per customer ($), gross margin (%), customer acquisition cost ($), monthly revenue churn (%). Collect them from a source document — a statement, a report, an invoice, a log — rather than from memory, because recalled inputs are the single largest cause of wrong results. One decimal place more than your data supports is one decimal place of fiction.
Step 2 — baseline before exploration. Get one defensible LTV : CAC ratio on screen before you start nudging numbers. Without a baseline, every variation looks interesting and none of them means anything. Repeating a calculation with the same numbers proves only that the arithmetic is reliable — which is worth knowing.
Step 3 — measure what deserves measuring. The ranked levers above tell you where a careful figure pays off. Everything else can stay approximate, which is a licence to stop hunting for data you do not need. Numbers are cheap to produce and expensive to retract; the extra minute is the cheapest insurance available.
Step 4 — ask what would have to be true. Take the result you want and work backwards through the inputs until you find the assumption that produces it; then decide honestly whether that assumption is defensible. The point of transparency is that a reader can disagree with a specific line rather than with you.
Step 5 — record the context, not just the number. Note today’s date and the inputs alongside the 12.78 × output. Six months from now the context is what turns this figure into a trend. Rounding early is the quietest way to introduce a permanent error.
Who actually uses Unit Economics — and when
Most Startup Metrics disagreements are arithmetic disagreements in disguise. When LTV : CAC ratio of 12.78 × sits on the table with its working shown, the conversation stops being about who sounds more confident and starts being about which input is wrong. The point of transparency is that a reader can disagree with a specific line rather than with you.
The audience for this page is people who need one trustworthy number before their next decision. In professional Startup Metrics practice the pattern is always the same — screen with Unit Economics, then invest slow analysis only in whatever survives the screen. When in doubt, prefer the boring input: the interesting one is usually the one you misread.
Nothing here is stored or transmitted, so the habit of checking is free: open the page, re-enter current figures, compare with the number you saved last time. The fastest sanity test is to guess the answer first and see how far the calculation disagrees.
The questions that come up most about Unit Economics
What affects Unit Economics the most?
The short answer: Customer acquisition cost. The longer answer is the sensitivity table on this page, where every numeric input was probed by ten percent and the LTV : CAC ratio recalculated — Customer acquisition cost moved it furthest, by roughly 11.1 % (11.62 × to 14.20 ×).
Do monthly revenue churn and customer acquisition cost matter equally?
On these inputs, yes: the two measured within a rounding error of each other — ≈11.1 % and ≈11.1 % of the LTV : CAC ratio per ten-percent change. Treat them as one pair to verify together rather than ranking them.
What is a typical Unit Economics?
There is no honest universal average for Unit Economics, but there is a reference point: the defaults on this page produce 12.78 × (Healthy unit economics). Replace the inputs with your own and compare — that comparison is the useful meaning of “typical”.
How do I calculate Unit Economics by hand?
LTV = ARPU × margin ÷ churn; ratio = LTV ÷ CAC; payback = CAC ÷ (ARPU × margin) is the entire method. Work the inputs in that order — Monthly contribution = $245 × 84% = $205.80 — and you will reach 12.78 × on the default figures, the same number this tool prints.
What happens to Unit Economics if customer acquisition cost changes by 10 %?
Try it in the form above and the printed substitution will follow you; the pre-computed answer for the defaults is 11.62 × to 14.20 × across the ten-percent probe, i.e. ≈11.1 % sensitivity on the LTV : CAC ratio.
Is the Unit Economics result of 12.78 × good or bad?
The tool answers “what”, not “whether”: 12.78 × carries the verdict “Healthy unit economics” for the default case, which is a starting interpretation rather than a verdict on your situation. Re-run with your own figures and compare the bands.
How often should I check Unit Economics?
Whenever an input changes by more than a few percent, and otherwise on the rhythm of your decisions — before a purchase, a review, a renewal. Unit Economics is a snapshot, not a subscription; stale snapshots are the most common silent error in Business & Entrepreneurship planning.
What does 12.78 × tell me about the business?
It answers the narrow question mechanically and the broad question only in context: Unit Economics is one dashboard light, and it pairs with unit economics and cash timing before any bet the business size.
Minimum acceptable ratio?
3× is the classic floor; below 1× growth destroys value, 1–2× usually stalls under scrutiny.
Should LTV be discounted?
Operationally no — undiscounted with a short payback is the diligence-proof standard.
Does this Unit Economics tool store my numbers?
No. The entire calculation runs in your browser session; nothing entered above is transmitted or saved, which is the correct behaviour for sensitive Business & Entrepreneurship figures and the reason you can re-run this page as often as you like.
What the labels on this page mean
- Customer lifetime
- 50.0 months on the example inputs — a companion figure printed beside the headline of Unit Economics so that no result is read in isolation.
- Lifetime value (gross-profit basis)
- $10,290 in the default Unit Economics calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- CAC payback period
- 3.9 months on the example inputs — a companion figure printed beside the headline of Unit Economics so that no result is read in isolation.
- LTV : CAC ratio
- The primary output of this tool: 12.78 × for the default inputs, computed exactly from LTV = ARPU × margin ÷ churn; ratio = LTV ÷ CAC; payback = CAC ÷ (ARPU × margin).
- Worked example
- Every substitution in order, from the example inputs to 12.78 × — the audit trail for the headline figure.
- Verdict band
- The interpretation attached to a result (“Healthy unit economics” on these inputs), which turns a bare number into a position on a scale.
- Sensitivity (±10 %)
- How far the Unit Economics moves when a single input is nudged ten percent either way; the ranked list on this page is computed live from this engine.
Method, sources and what this tool cannot tell you
Everything above runs on one stated formula, applied without hidden coefficients: LTV = ARPU × margin ÷ churn; ratio = LTV ÷ CAC; payback = CAC ÷ (ARPU × margin). Source of record: Bessemer / a16z unit-economics conventions. Any other implementation of this model should return the same figure for the same inputs. If one does not, the difference is in its assumptions — which this page prints and that one probably does not.
Treat the output as a precise answer to the question you typed: exact arithmetic, transparent formula, published source, no hidden rounding. Nothing is smoothed, weighted or adjusted behind the scenes; where judgement enters, this page says so and names the input responsible.
Turning this Unit Economics into a decision
Save the number together with its inputs and today’s date; a Unit Economics figure without context is unusable the moment an input changes.
The audience here is people who need one trustworthy number before their next decision. Everything you need to defend the result — formula, substitution, sensitivity, source — is printed above, so the only remaining variable is the honesty of your inputs.