Is the percentage calculator free to use?

Yes. It’s free and runs in your browser - no signup, no install.

How do I find X% of a number?

Pick the ‘What is X% of Y’ mode, type the percentage and the number, and read the result. For example, 18% of 2500 = 450.

How do I calculate percent increase or decrease?

Use the change mode. Enter the old and new values - the tool returns the percent change: (new − old) / old × 100.

Can I add tax or GST using percentages?

Yes. Use the ‘X% change from Y’ mode to increase a base amount by a percentage - ideal for adding tax, service charges, or markups.

Are there rounding issues?

Only round the final value. Rounding mid-calculation introduces small errors. The tool keeps full precision internally and displays the rounded result.

Does the tool store my numbers?

No. Calculations run in your browser and aren’t stored on our servers.

Percentage Calculator

Calculate percentages, percentage increases, and decreases

Confidentialité d’abord • Aucune collecte de données

Calculatrice de pourcentages (Pro)

Calculez des pourcentages, augmentations, diminutions, remises et croissance composée. Obtenez des explications étape par étape pour mieux comprendre.

Calculatrice de pourcentages

Sélectionnez le type de calcul et saisissez vos valeurs

Type de calcul

Pourcentage (%) *

De la valeur *