Every formula you need, explained simply — with interactive calculators and exam-style practice questions to test yourself.
These formulas are NOT given to you in the exam — you need to remember them. Bookmark this page and test yourself regularly.
These are the building blocks — everything else is built on top of these.
Fixed costs stay the same no matter how much you produce — rent, insurance, manager salaries.
Variable costs go up as you produce more — raw materials, packaging, delivery.
Why do margins matter? A business might have huge gross profit in pounds but if its margin is low, it's not very efficient. A 5% net profit margin means for every £1 of sales, only 5p is actual profit. Margins let you compare businesses of different sizes fairly.
| Item | Amount |
|---|---|
| Revenue | £850,000 |
| Cost of Sales | £340,000 |
| Expenses | £255,000 |
The break-even point is the number of units a business needs to sell so that its revenue exactly equals its total costs — it's making neither a profit nor a loss.
Quick example: Fixed costs = £10,000. Selling price = £50. Variable cost per unit = £30.
Contribution per unit = £50 − £30 = £20.
Break-even = £10,000 ÷ £20 = 500 units.
If the business currently sells 650 units, the margin of safety = 650 − 500 = 150 units.
Cash flow shows the money coming into and out of a business each month. A profitable business can still run out of cash — so monitoring this is crucial.
Inflows = money coming IN: sales revenue, loans received, investment.
Outflows = money going OUT: wages, rent, raw materials, loan repayments, marketing.
Fill in the missing values for FreshBloom, a flower shop. Click "Check answers" when done.
| Item | Jan | Feb | Mar |
|---|---|---|---|
| Sales Revenue | £8,000 | £6,500 | £9,200 |
| Other Inflows | £1,000 | £0 | £500 |
| Total Inflows | £6,500 | ||
| Wages | £3,200 | £3,200 | £3,200 |
| Stock / Materials | £2,100 | £1,800 | £2,400 |
| Rent & Overheads | £1,500 | £1,500 | £1,500 |
| Total Outflows | £6,800 | £7,100 | |
| Net Cash Flow | |||
| Opening Balance | £500 | ||
| Closing Balance |
ARR tells you how profitable an investment is as a percentage of its cost. Businesses use it to compare two different investment options and choose the better one.
Step-by-step:
1. Work out the total profit from the investment over its whole life (total returns − initial cost)
2. Divide by the number of years to get average annual profit
3. Divide by the initial investment and multiply by 100 to get the %
How to use it: If investment A has an ARR of 18% and investment B has an ARR of 12%, choose A — it returns more profit per pound invested per year.
| Year | Net Return |
|---|---|
| Year 1 | £12,000 |
| Year 2 | £14,000 |
| Year 3 | £16,000 |
| Year 4 | £18,000 |
Calculate the ARR of the machinery investment. Give your answer to 1 decimal place.
Percentages come up all over the exam — in market share, percentage change, interest calculations, and more.
These questions mix everything together just like the real exam. Work through them all, show your working, then check your answers.
(a) Calculate Nova Bikes' total revenue last month. [2]
(b) Calculate the break-even output for Nova Bikes. [2]
(c) Calculate the margin of safety. [2]
(d) Calculate the gross profit margin. [2]
(e) Calculate the net profit margin. [2]