What it means
The ratio is also called the quick ratio, and it is a tougher sibling of the current ratio. Where the current ratio counts every current asset, the acid-test strips out inventory and prepaid expenses, on the grounds that neither can be reliably converted into cash within days.
Lenders and credit controllers watch it closely because it answers a specific question: if trade dried up tomorrow, could this business still pay its suppliers, its tax bill and its short term loans? A company can look comfortable on the current ratio and alarming on the acid-test if most of its current assets are slow moving stock.
The healthy range depends heavily on the business model. A supermarket chain can run happily at 0.3 because it sells inventory for cash long before it pays suppliers, whereas a machinery manufacturer with 90 day customer terms would be under real strain at the same level.
Reading the ratio well means looking at what sits inside the numerator. Receivables count as quick assets in theory, but if a third of them are more than 90 days overdue then the ratio is flattering the true position, so ageing analysis belongs alongside the number.
Trend matters more than any single reading. A ratio drifting from 1.4 down to 0.9 over four quarters signals a working capital problem building quietly, and it usually shows up here before it shows up in the profit figures.
In practice
Real-world examples
Example 1
A bank reviewing a $400,000 overdraft facility sees a manufacturer with a current ratio of 2.1 but an acid-test of 0.6. The gap is $900,000 of slow moving spare parts inventory, so the bank offers a smaller facility secured against receivables instead.
Example 2
A software business runs an acid-test ratio of 3.4 because it holds no inventory at all and collects annual subscriptions upfront. Its board treats anything below 2.0 as a signal to slow hiring.
Example 3
A restaurant group shows an acid-test of 0.4 and its auditors are relaxed about it. Customers pay instantly by card while suppliers are paid on 30 day terms, so the business is funded by its own payables rather than by holding liquid assets.
Think of it
Acid-test strips inventory away-can you pay bills just with cash and receivables?
Formula
Calculation
Acid-test ratio = (Cash + short term investments + accounts receivable) / current liabilities
An equivalent version is: (Current assets - inventory - prepaid expenses) / current liabilities
A specialist equipment distributor reports cash of $250,000, short term investments of $100,000 and accounts receivable of $350,000, giving quick assets of $250,000 + $100,000 + $350,000 = $700,000. Its current liabilities are $560,000, so the acid-test ratio is $700,000 / $560,000 = 1.25.
The cross check works too. Total current assets are $1,200,000, of which inventory is $450,000 and prepaid expenses are $50,000, so $1,200,000 - $450,000 - $50,000 = $700,000, and $700,000 / $560,000 = 1.25 again. For contrast, the current ratio is $1,200,000 / $560,000 = 2.14, which is why looking only at the current ratio would have made this business appear far more liquid than it is.Case study
Seen in the real world
This is an illustrative and fictional scenario. Cobalt Fixings, an invented industrial fastener wholesaler, grew revenue 22% in a year and its management reported a current ratio of 2.3, which everyone read as comfortable. The finance director then calculated the acid-test ratio and found it had fallen from 1.1 to 0.68 across the same period.
The cause was straightforward once the numbers were separated. Inventory had grown from $1,900,000 to $3,400,000 as the sales team added product lines, while cash and receivables had barely moved, so the growth had been funded almost entirely by turning cash into stock that was not selling.
Cobalt's illustrative response was a stock clearance on 400 slow lines and a rule that any new product had to be sold from consignment for two quarters before being bought outright. Within nine months the acid-test ratio was back above 1.0, and the company avoided the emergency borrowing that its cash forecast had been quietly predicting.
Watch out
Common mistakes
- Including inventory or prepaid expenses in the numerator, which turns the acid-test ratio into the current ratio and defeats the whole point of the measure.
- Judging every industry against a benchmark of 1.0, when retail and hospitality run safely far below it and project based businesses need much more.
- Counting the full receivables balance as liquid without checking how much of it is overdue or disputed, which overstates real short term cover.
Questions
People also ask
Why is inventory excluded when it is a current asset?
Because turning stock into cash requires finding a buyer, agreeing a price and waiting for payment, which is exactly what a business under pressure cannot do quickly.
Is a very high acid-test ratio always good news?
Not necessarily, since a ratio of 4 or 5 can mean cash is sitting idle instead of funding growth, paying down debt or being returned to shareholders.
Should an undrawn overdraft or credit line be included?
Not in the standard calculation, though analysts often mention available facilities alongside the ratio because they materially change the liquidity picture.
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