Free · Percentages calculators 💯

Decimal ↔ Percentage Converter

Convert a decimal proportion into percent, or turn a percentage number back into its decimal form.

  • Formula & worked example
  • Private in your browser
  • No signup
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

0.375 equals 37.5%. In reverse, enter 37.5 in the percentage field to get the decimal 0.375.

Percentage number = decimal × 100; decimal = percentage number ÷ 100

Worked example

Enter these known values and leave the other values blank.

Decimal value
0.375
Percentage value
37.5 %

Assumptions and limitations

  • The percentage field expects the displayed number before the percent sign: enter 37.5 for 37.5%.
  • Values above 100% and negative percentages are valid numeric conversions. They are not automatically valid probabilities or physical proportions.
  • This changes the representation of one number; it does not calculate a percent increase or a percentage of another amount.

Common questions

What does 100% equal as a decimal?

100% equals 1. Similarly, 250% equals 2.5.

Should I type the percent sign?

Enter only the numeric value. The percentage field displays its percent sign separately.

References

The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.

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