A financial ratio is a question asked in arithmetic. Can this business pay what falls due this month? Does each sale leave anything behind? How long is cash tied up before it comes back? Can it carry its debt? The fourteen calculators below answer those four questions, and the point of grouping them is that a single ratio read alone is usually misleading — Current Ratio Calculator above 2 looks safe until you see that most of the assets are unsold inventory.
Pricing & Margin
Profit Margin CalculatorWork out gross, contribution, operating, and net margin, with target pricing, break-even, scenarios, and SKU comparison.
Marketing
Break-Even ROAS CalculatorWork out break-even and target ROAS from your real margins, plus max CAC, break-even MER, and ad budgets.
Working Capital
Cash Conversion Cycle CalculatorWork out the days between paying suppliers and being paid by customers, on one consistent day basis, then see what each day is worth in cash.
DSO CalculatorDays sales outstanding by the simple ratio and by countback, with the floor your payment terms set separated from genuine lateness.
DIO CalculatorDays of stock on hand against cost of goods sold, with the turnover it implies and the revenue-denominator mistake priced beside it.
DPO CalculatorDays payable outstanding on COGS or on derived purchases, with the annualised cost of skipping an early-payment discount.
Liquidity
Current Ratio CalculatorShort-term assets over short-term debts, with the quick and cash tests beside it — and a live demonstration of how settling payables moves the number.
Quick Ratio CalculatorThe acid test by both formulas in circulation, with the exact size of their disagreement and what causes it.
Cash Ratio CalculatorThe strictest liquidity test, shown as the last rung of a ladder with the money each step removes.
Working Capital CalculatorCurrent assets minus current liabilities, measured against what your cash conversion cycle actually requires.
Leverage & Solvency
Interest Coverage Ratio CalculatorTimes interest earned on EBIT and on EBITDA, with the debt service coverage beside it so the principal is not invisible.
Altman Z-Score CalculatorAll three published models at once — different coefficients, different thresholds — with a warning when they disagree about the same company.
Startup Finance
Burn Rate CalculatorGross and net burn from cash, costs and revenue, and the months of runway left at that rate.
Operations & Tools
Stock Coverage CalculatorHow many days and weeks of selling your current stock covers, set against the lead time to replace it.
Liquidity: can it pay what falls due
Three ratios ask the same question with progressively stricter definitions of what counts as available money, and reading them together is the whole technique. Current Ratio Calculator counts every current asset against every current liability. Quick Ratio Calculator removes inventory, because stock that has not sold is not cash and may never be. Cash Ratio Calculator removes receivables too, leaving only money already in the bank. A business whose current ratio is 2.1 and whose cash ratio is 0.2 is not liquid; it is holding a lot of stock and waiting on a lot of invoices. The gap between the three is the diagnosis, not any one of them. Working Capital Calculator states the same position in currency rather than as a multiple, which is the form a bank usually asks for.
Efficiency: how long cash is tied up
A profitable business can still run out of money, and these four say where it goes. DIO Calculator measures the days stock sits before it sells. DSO Calculator measures the days between invoicing and being paid. DPO Calculator measures how long the business takes to pay its own suppliers, which is a source of funding rather than a cost. Cash Conversion Cycle Calculator combines all three into the number that matters: days of working capital the business must finance by itself. A negative cycle means suppliers fund the business before customers pay, which is why some retailers grow without borrowing. Stock Coverage Calculator answers the related question of how long current stock will last at the current rate of sale.
Profitability: what each sale leaves behind
Profit Margin Calculator separates gross, operating and net margin, and the distance between them is where the money goes — gross margin is the product, operating margin is the overhead, net margin is everything else including interest and tax. Break-Even ROAS Calculator asks the advertising version of the same question: the return on ad spend at which a campaign stops losing money, which depends entirely on the margin above. A campaign at 3× ROAS is profitable at a 40% margin and loss-making at 20%.
Leverage and survival: can it carry the debt
Interest Coverage Ratio Calculator divides operating profit by interest expense, and it is the ratio a lender looks at first: below about 1.5 the business is one bad quarter from missing a payment. Burn Rate Calculator answers the startup form of the question — how fast reserves are being consumed, and how many months remain. Altman Z-Score Calculator combines five ratios into a single distress score; treat it as a screening signal rather than a verdict, because it was fitted on manufacturers and reads differently elsewhere.
One business, read four ways
Take a small distributor with £400,000 of current assets, of which £240,000 is stock and £30,000 is cash, against £190,000 of current liabilities. Its Current Ratio Calculator is 2.1, which reads as comfortable. Strip the stock and the Quick Ratio Calculator is 0.84 — under 1, meaning it cannot cover this month from receivables and cash alone. Strip receivables too and the Cash Ratio Calculator is 0.16. The same balance sheet is either safe or tight depending on which of the three you stop at, and the honest reading is the third. Now ask where the money went. If stock turns in 90 days and customers pay in 45 while suppliers are paid in 30, Cash Conversion Cycle Calculator puts 105 days of working capital on the business itself — which is exactly the £240,000 sitting as stock. The liquidity problem and the efficiency problem are the same problem seen twice. Whether it can be carried is the last question. At £60,000 of operating profit against £24,000 of interest, Interest Coverage Ratio Calculator is 2.5: serviceable, but a 40% fall in profit takes it to 1.5, which is where lenders start asking. None of those four numbers is alarming alone. Together they describe a business that is profitable, solvent on paper, and one slow quarter from a cash problem.
What a ratio cannot tell you
Every number on these pages comes from a balance sheet or an income statement, and those are a snapshot taken on a chosen day. A business that collects its receivables the week before year end reports a different Current Ratio Calculator from the same business measured a fortnight earlier, with nothing real having changed. Seasonal trades show this most sharply: a retailer measured in November is carrying stock it will have sold by January. Comparisons across industries mislead for the same reason. A supermarket runs on a current ratio below 1 and is perfectly sound, because it sells for cash and pays suppliers later; a shipbuilder with the same figure is in trouble. Read a ratio against the same business last year, and against its own trade, not against a textbook target. And none of them sees the things that sink companies fastest — a customer that is 40% of revenue, a covenant that trips on a ratio you are not tracking, a supplier with no second source. The arithmetic here is exact. What it measures is only part of the picture.
Reading them together
No single ratio is an answer. Liquidity without efficiency tells you the business can pay this month but not why cash is tight. Margin without leverage tells you sales are profitable but not whether the interest bill eats them. The practical order is: margin first, because a business that loses money on every sale cannot be fixed by working capital; then the cash cycle, because that is what actually consumes the money; then liquidity, to see whether it can survive the gap; then coverage, to see whether the debt is carryable. Each calculator shows its formula and its own worked example, so the arithmetic is checkable rather than taken on trust.