How do I find what percentage one number is of another?

Divide the part by the whole and multiply by 100. For 20 out of 80, the result is 25%. The whole cannot be zero; the working names the divisor.

Can I calculate attendance, occupancy or a percentage of hours?

Yes, from numeric totals. Attending 18 of 20 sessions is 90%; 30 occupied rooms out of 40 is 75%; 12 hours out of 40 is 30%. Use the same units in both boxes. Convert a clock time such as 1:30 to 1.5 hours first; no institutional attendance requirement is chosen.

Does the part have to be smaller than the whole?

No. A supplied part of 120 against a reference whole of 100 is 120%. Negative inputs are also numeric arithmetic, not counts of physical objects; decide what your denominator represents.

Can I calculate net, operating or food-cost percentages?

For supplied matching totals, use the amount as the part and revenue or the relevant total as the whole. Net income 75 out of revenue 1,000 is a 7.5% net margin; food cost 30 out of sales 100 is 30%. The tool does not compute taxes, expenses, food quantities or an industry target for you.

What Percent Is One Number of Another?

Enter the amount you have and the whole it belongs to. This page starts with 20 out of 80: 20 ÷ 80 × 100 = 25%. Attendance, occupied spaces, hours and known net-income/revenue ratios use the same part-to-whole arithmetic when the two inputs share units. It does not infer a school threshold, parse clock times or decide which costs belong in an accounting total.

20 is what percent of 80?25%20 ÷ 80 × 100

Question

This number

Out of

The working
20 ÷ 80 × 100
Computed result
25%

Change and difference are not the same thing. Going from 80 to 100 is a 25% increase, measured against where you started. But the percentage difference between 80 and 100 is 22.22%, because that one divides by the average of the two. Change has a direction; difference does not. Reports and spreadsheets mix these up constantly, which is why both are here as separate questions.

Margin and markup are the same profit over two different divisors. Something that costs 40 and sells for 100 earns 60 either way, but the margin divides that by the selling price and is 60%, while the markup divides it by the cost and is 150%. Margin can never pass 100%; markup has no ceiling. The profit margin question above reports both, each beside the number it divided by.

Common questions

How do I find what percentage one number is of another?: Divide the part by the whole and multiply by 100. For 20 out of 80, the result is 25%. The whole cannot be zero; the working names the divisor.
Can I calculate attendance, occupancy or a percentage of hours?: Yes, from numeric totals. Attending 18 of 20 sessions is 90%; 30 occupied rooms out of 40 is 75%; 12 hours out of 40 is 30%. Use the same units in both boxes. Convert a clock time such as 1:30 to 1.5 hours first; no institutional attendance requirement is chosen.
Does the part have to be smaller than the whole?: No. A supplied part of 120 against a reference whole of 100 is 120%. Negative inputs are also numeric arithmetic, not counts of physical objects; decide what your denominator represents.
Can I calculate net, operating or food-cost percentages?: For supplied matching totals, use the amount as the part and revenue or the relevant total as the whole. Net income 75 out of revenue 1,000 is a 7.5% net margin; food cost 30 out of sales 100 is 30%. The tool does not compute taxes, expenses, food quantities or an industry target for you.

Browser double-precision arithmetic. Decimal results are rounded to twelve significant digits; safe integer results retain their full value. The formula shows the inputs used.