A ratio nobody can read is a number, not an answer.

Put in whatever figures you have. Every ratio comes back with its formula and a sentence saying what it means — and anything the figures do not support is listed as missing rather than quietly worked out from a zero.

From the balance sheet

Current assets

Current liabilities

Closing stock

Debtors

Creditors

Capital employed

Long-term debt

Equity

From the trading and profit and loss account

Sales

Cost of sales

Gross profit

Net profit

Average stock

Credit sales

Credit purchases

Mark-up is not margin

Both are gross profit over something, and the something is different: margin is over sales, mark-up is over cost. The same trade gives 40% margin and 66.7% mark-up. Swapping them is the commonest slip in this topic, so both are shown.

Nothing is assumed

A blank is a blank, not a zero. If a figure is missing the ratio is not worked out and the page says which figure it wanted. A confident number built on an assumption looks exactly like one that means something.

What a ratio cannot tell you

Whether the figures behind it are right, what the trade is like, or what the same business did last year. A ratio is a question worth asking, not an answer — and a current ratio of 2 is comfortable for a shop and alarming for a bank.