Convert a percentage to a decimal (and its fraction) or a decimal back to a percentage.
Numbers • percent
Encoding and decoding share the page, so any result can be pasted straight back to confirm it round-trips to the text you started with — the quickest check that nothing was mangled.
Results are recalculated on every keystroke, with no submit step and no page reload, so a value can be adjusted until the answer looks right rather than guessed once.
Everything runs in your browser — no account, no uploads, nothing leaves your device.
Percentages, decimals and fractions are three ways of writing the same proportion: 25% = 0.25 = 1/4. Converting between them is everyday math for finance, statistics, discounts, tips, grades and probability.
Enter a percent to get its decimal and simplest fraction, or switch direction to turn a decimal into a percentage. Instant, accurate and browser-based.
Percent literally means "per hundred", so converting to a decimal is division by 100 and converting back is multiplication by 100 — mechanically trivial, and the source of persistent errors in spreadsheets and code because the mistake is silent. Entering 0.08 into a cell formatted as a percentage displays 8%, while entering 8 into the same cell displays 800%, and both are valid numbers that produce no warning. The related trap is percentage points versus percent: a rate moving from 4% to 6% has risen two percentage points but fifty percent, and those describe very different things.
Decimal = Percent ÷ 100Percent = Decimal × 100Basis point = 0.01% = 0.0001 as a decimalPercentage point ≠ percent changewhere:
Assumptions: Most spreadsheet and programming functions expect decimals, not percentages. A rate entered as 5 instead of 0.05 produces results wrong by a factor of 100, which is usually obvious — and sometimes not, in a compounding formula.
Convert in both directions and separate percentage points from percent change.
Result4% = 0.04 · 175 bps = 1.75% = 0.0175
Basis points exist precisely to avoid the point-versus-percent ambiguity: "the rate rose 200 basis points" is unambiguous where "the rate rose 2%" is not. Financial writing uses them for exactly that reason.
Moving between a percent and a decimal is a shift of two places, but the arithmetic that follows is where percentages cause trouble. A rise from 4% to 5% is an increase of one percentage point and simultaneously a relative increase of 25%, and both statements are correct. Reporting that mixes the two — describing a one-point move as a 1% change — is common enough that finance introduced a third unit, the basis point, defined as one hundredth of a percentage point, purely to remove the ambiguity.
Percentage changes also do not add up, which is the second recurring error. Two successive falls of 10% do not make 20%: multiplying by 0.9 twice leaves 0.81, a fall of 19%. For the same reason a 50% loss requires a 100% gain to recover, and a discount applied after a markup does not return the original price. Percentages compose by multiplication, and any calculation that chains them has to be done that way.
The base matters as much as the number. A percentage is always of something, and the something can change between the two figures being compared — a share of a growing total, a rate applied to a different denominator, a proportion of respondents who answered rather than of those asked. Converting the notation is trivial; identifying what the denominator was is the part that determines whether the comparison means anything.