The formula
How to calculate cash conversion cycle
The cash conversion cycle counts the days between cash leaving the business to buy stock and cash arriving from the customer who bought it. Every day in that gap has to be funded from somewhere.
Three components: how long stock sits, how long customers take to pay, and how long you take to pay suppliers. The last one is subtracted because supplier credit is free finance covering part of the gap.
Fill in the following:
- Days inventory outstanding (days)
- Days sales outstanding (days)
- Days payable outstanding (days)
The result updates on every keystroke. The URL updates too, which makes the filled-in version easy to bookmark or send to someone else.
The order the fields are filled in makes no difference to the result — the calculator recomputes the whole formula from whatever is currently in every field, not step by step. That means it is safe to adjust one number, watch the result change, and adjust it back, without worrying about resetting anything first.
Why cash conversion cycle matters
The formula behind cash conversion cycle is standard and has not changed in decades; what changes is the situation it gets applied to. Two households can run the identical calculation and land on very different conclusions once their own numbers — income, rate, term, balance — are dropped in, which is why a generic textbook example is less useful than a calculator you can adjust to match your own circumstances.
This tends to come up when comparing two concrete alternatives — two lenders, two savings products, two ways of structuring the same decision — rather than in the abstract. Run both scenarios through the same calculator with the same assumptions and the comparison becomes fair, because the only thing changing between the two results is the number you are actually trying to test.
It is also worth being clear about what a single figure like this can and cannot settle on its own. It answers the specific question the formula was built to answer, and nothing more — a favourable cash conversion cycle result does not automatically mean a decision is a good one overall, since plenty of other factors that a formula cannot capture, from personal circumstances to how comfortable a commitment feels, usually matter just as much as the arithmetic. Use the number as one solid input among several rather than the whole of the decision.
In practice, most people arrive at a page like this one having already tried a version of the calculation by hand or in a spreadsheet, and use the calculator here to confirm it rather than replace it. That is a reasonable way to use it — the two should agree to the last decimal place if the same inputs and the same formula are used, and if they do not, the formula shown above is the one to check your own working against first.
Worked example
Work through the defaults on this page:
- Days inventory outstanding: 52 days
- Days sales outstanding: 41 days
- Days payable outstanding: 35 days
That gives:
- Cash conversion cycle: 58 days
- Operating cycle: 93 days
- Days financed by suppliers: 35 days
These figures are only the calculator's own starting values, included so the working is visible rather than hidden inside the tool above. Replace them with your own numbers and the same arithmetic applies — nothing about the method changes, only the inputs feeding it.
Reading the result
Shorter is better, and negative is excellent — it means customers pay before suppliers do. Cutting the cycle by ten days on a £2.4 million business releases around £65,000 of cash permanently.
Where this goes wrong. Stretching payables to improve the number. It works on paper and damages supplier relationships, priority during shortages and pricing — a cheap way to make a ratio look better and an expensive way to run a business.
A useful check on any unfamiliar result is to compare it against a rough mental estimate first — round the inputs to convenient numbers and see whether the calculator's answer lands in roughly the same territory. A wildly different figure usually means one of the fields was entered in the wrong unit, most often a percentage typed as a whole number where a decimal was expected, or the reverse.
It depends entirely on the model. Retailers often run negative; manufacturers commonly sit at 60–100 days. Track your own trend rather than an absolute target.
Invoice on the day of delivery, chase before the due date, offer small early-settlement discounts, and reduce slow-moving stock. Improving collections is usually faster and cheaper than renegotiating supplier terms.
The answer it gives you is cash conversion cycle. With 52 days days inventory outstanding, 41 days days sales outstanding and 35 days days payable outstanding, that comes to 58 days. Change any field and the figure moves with it.
Whenever one of the underlying figures changes — a new interest rate, a different balance, an updated term — since the result only reflects what is currently in the fields. There is no need to keep a separate record of past results; the web address for a filled-in version already carries the figures used to produce it.
Not unless a tax rate or a fee is explicitly one of the inputs above. Where it is not, the figure shown is a gross calculation, and any tax due depends on your personal circumstances and current tax rules, which are worth checking separately.
The arithmetic itself is exact — the calculator applies the formula shown above precisely, with no rounding until the final figure is displayed. The uncertainty, where it exists, is entirely in the inputs: an estimated rate or an approximate balance carries that same approximation through to the result.