Decimal to Percent Calculator

A percentage is just a decimal multiplied by 100. 0.75 turns into 75%. Going the other way, 25% becomes 0.25. That's the whole conversion. You'll see this math constantly in discounts, test scores, interest rates, and probability. Type a number into either field below and the other one fills in.

The conversion in detail

To go from decimal to percent, multiply by 100 and add the % sign. To go from percent to decimal, drop the % sign and divide by 100. So 0.5 × 100 = 50%, and 75 ÷ 100 = 0.75.

\begin{aligned}\text{Decimal to Percent:} \quad & 0.5 \times 100 = 50\% \\\text{Percent to Decimal:} \quad & 75 \div 100 = 0.75 \\\text{Shortcut (Shift 2 places):} \quad & 0.35 \longrightarrow 35\% \\& 45\% \longrightarrow 0.45\end{aligned}

A faster version of the same trick: shift the decimal point two places. 0.35 becomes 35%, and 45% becomes 0.45.

Using the calculator

Type a decimal into the Decimal field and read the percentage. Or type a percentage into the Percentage field and read the decimal. Both fields accept negative values and decimals greater than 1, which give you percentages above 100%.

Common conversions

Memorizing a few of these speeds up everyday mental math.

Decimal	Percentage	Description
0.1	10%	one tenth
0.25	25%	one quarter
0.5	50%	one half
0.75	75%	three quarters
1.0	100%	the whole
1.5	150%	one and a half times
0.005	0.5%	half of one percent

Where this comes up

A test score of 0.87 is an 87%. A 0.20 discount is 20% off. An interest rate written as 0.05 is the same 5% you see on a loan ad. Probabilities also flip between the two forms: a 0.3 chance of rain is a 30% chance. Anywhere a fraction of a whole shows up, this conversion shows up with it.

Quick mental math

The fastest method is the decimal-point shift. Going from decimal to percent, slide the decimal two places to the right (0.35 → 35%). Going back, slide it two places to the left (45% → 0.45). Knowing the common ones cold (0.5 = 50%, 0.25 = 25%) covers most of what you'll bump into day to day.

Frequently asked questions

Can a decimal be greater than 1?

Yes. Anything over 1 converts to a percentage above 100%. 2.5 becomes 250%, which usually represents growth above the original value (a stock that tripled, a result 2.5x the baseline).