How To Calculate Customer Lifetime Value

Customer lifetime value multiplies what a customer pays each month by the share of that revenue the business keeps, then stretches the result across however long the customer stays. With an average revenue per user of 50 a month, a gross margin of 70 per cent and monthly churn of 4 per cent, the contribution is 35 a month and the average lifetime is 25.0 months, so the lifetime value is 875.0. The formula reads LTV = ARPU x gross margin / churn. Read it as three decisions rather than one: how much the customer pays, how much of that survives the cost of serving them, and how long they remain.

The margin step is what turns a revenue figure into a contribution figure, and skipping it is the single most expensive shortcut in the calculation. Using the full 50 a month over 25.0 months gives 1250, but the business never keeps 50; after the cost of serving the customer only 35 remains, and 35 x 25 = 875.0. The 375 difference is not a rounding matter, it is the difference between a plausible investment and an imaginary one. LTV is therefore a contribution measure: it counts the money available to repay acquisition, not the money that passes through the till.

Churn sets the lifetime, and it does so through a reciprocal rather than a subtraction. A monthly churn rate of 4 per cent, written as 0.04, implies an average life of 1 / 0.04 = 25.0 months. Halve the churn to 2 per cent and the lifetime doubles to 50 months; double it to 8 per cent and the lifetime falls to 12.5 months. This inverse relationship is why retention improvements compound so powerfully: a single point of churn, from 4 per cent to 3 per cent, lifts the average lifetime to 33.33 months and the lifetime value from 875.0 to 1166.67.

The worked case keeps every number visible. ARPU is 50 a month, gross margin is 70 per cent, and monthly churn is 4 per cent. Applying the margin gives a contribution of 50 x 0.70 = 35.0 a month. Applying churn gives an average lifetime of 1 / 0.04 = 25.0 months. Multiplying the two gives 35.0 x 25 = 875.0, the lifetime value. Every later comparison on this page descends from those four numbers, which is why they should be written down before any ratio is quoted.

Lifetime value only becomes a decision when it is divided by the cost of winning the customer. With a customer acquisition cost of 250, the ratio is 875 / 250 = 3.5. The usual rule of thumb is a floor of at least 3 to 1, so 3.5 clears it, but not by much. Ratios below 1 mean each new customer destroys value the moment they sign; ratios above 5 usually signal that growth is being underfunded rather than that the business is unusually efficient.

Two quiet choices move the answer more than most people expect. The first is whether future contribution is discounted: 875.0 is the undiscounted total, and applying a discount rate pulls it down, because month twenty-five is worth less than month one. The second is whether the margin is gross or net. Gross margin excludes the direct cost of serving the customer; a net figure also removes support, payment fees and overheads. If the honest margin were 60 per cent rather than 70, contribution would be 30 rather than 35.0 and lifetime value 750 rather than 875.0.

Lifetime value is a planning estimate, not an accounting figure, and treating it as the latter causes real damage. It multiplies an average revenue by an average margin and divides by an average churn rate, so it describes a cohort that has not finished living yet. No auditor will certify it, no balance sheet carries it, and two analysts using defensible assumptions can differ by a factor of two. Its job is to rank options and set spending limits, not to report what happened. Quoted to the nearest hundred it guides decisions; quoted to two decimal places it merely pretends to precision.

Because lifetime value is an average, it hides the shape of the customer base. One channel might deliver customers worth 875.0 and another customers worth 300, blending into a respectable-looking middle figure while half the budget is spent badly. The same averaging problem applies to churn: a business losing 4 per cent a month overall may be losing 1 per cent of its annual customers and 9 per cent of its monthly ones. Segmenting by channel, plan and cohort is what turns a single number into something a budget can act on.

The levers that raise lifetime value are not all about price. Retention extends the 25.0-month lifetime; expansion revenue raises the 50 ARPU without changing churn; and margin discipline lifts the 35.0 contribution. Of the three, retention usually moves the number fastest, because churn sits in the denominator of the lifetime calculation. A business that keeps customers for 33.33 months instead of 25.0 has raised lifetime value by a third without winning a single extra customer, which is why the metric belongs beside acquisition cost rather than instead of it.