Calculators

Each calculator shows its formula, a worked example and its limitations.

• Percentage calculator: find X% of a numberUse this to answer questions like “what is 20% of 185?” — handy for tips, commissions, tax amounts and test scores.
• Percentage change calculatorCompare an original value with a new one to see how much it rose or fell, as a percentage of the original.
• Discount calculator: sale price after a percentage offWork out what you’ll actually pay when something is marked down by a percentage.
• Original price calculator: work back from a percentageKnow what you paid and the percentage, but not the starting price? This works it back.
• Tip calculator and bill splitterAdd a tip to a restaurant or service bill and split it evenly so the shares add up exactly.
• Profit margin calculatorSee how much of each sale you keep after the cost of the item, as a share of the selling price.
• Markup calculator: selling price from costStart from what an item costs you and a markup percentage to find the price to charge.
• Hours worked calculator with breaksWork out paid time for a shift from clock-in and clock-out times, minus an unpaid break.
• Unit price calculator: compare two sizesFind out which package is cheaper per ounce, gram, sheet or item.
• Days between dates calculatorCount calendar days between two dates — for deadlines, notice periods, trips or countdowns.