Percent Calculator Tool
Calculate percentages with 8 patterns. Includes double discount and double markup calculations.
Percent Calculator
of
%
is
?
e.g. 20% of 100 → 20
is
of
?
%
e.g. 30 is what % of 120? → 25%
is
%
of total
?
e.g. If 25 is 10%, total is → 250
to
change is
?
%
e.g. 100 to 120 → +20%
plus
%
is
?
e.g. 100 + 10% → 110
minus
%
is
?
e.g. 1000 - 30% → 700
Advanced
Double Discount
%
off, then
%
off = total
?
%
off
e.g. 20% off then 10% off = 28% off total (not 30%!)
Double Markup
%
up, then
%
up = total
?
%
up
e.g. 20% up then 10% up = 32% up total (not 30%!)
Calculation Modes (with formula)
Switch modes with the tabs; as you type, the formula and result appear below.
of
%
is
?
Formula—
is
of
?
%
Formula—
to
change is
?
%
Formula—
with
%
increase =
?
Formula—
at
%
discount =
?
Formula—
How to Use
1
Choose Pattern
Select from 6 basic + 2 advanced calculation patterns.
2
Enter Values
Results appear in real-time as you type.
3
Copy Result
Click the copy button to copy the result.
About Percent Calculator
Percentages represent parts per hundred and are widely used for discounts, growth rates, achievement rates, and tax calculations. This tool supports 6 basic patterns plus double discount and double markup calculations.
Features
- 8 PatternsFrom basic to double discount and markup.
- Real-time CalculationResults appear instantly as you type.
- Copy ResultsCopy calculation results with one click.
- Completely FreeNo registration or installation required.
Use Cases
- Sale and discount price calculation
- Tax and fee calculation
- Goal achievement rate
- Growth and change rate calculation
- Test score percentage
Related Tools & Guides
- Use the Percentage Change Calculator for year-over-year and change rates.
- Use the Discount Calculator to quickly find the price after a sale.
- Use the Consumption Tax Calculator (in Japanese) to convert between tax-exclusive and tax-inclusive amounts.
- Read the Percentage Basics Guide to understand the formulas.
FAQ
Is the percent calculator free?
Yes, it is completely free. No registration required.
Can I use decimal numbers?
Yes, decimal numbers are calculated accurately.
What is double discount?
It calculates the total discount when applying two discounts in sequence. For example, 20% off then 10% off equals 28% off total, not 30%.
What can I do in the Calculation Modes tab?
You can switch between five modes: "X% of Y", "X is what % of Y", "Change rate", "Value after +/- X%", and "Discount / Tax". Each mode shows the actual formula as you type (e.g., 100 × 20 ÷ 100 = 20) so you can verify how the answer is derived.
How do I switch between discount and tax?
Use the "Discount / Tax-incl." toggle inside the "Discount / Tax" mode. Discount is amount × (1 − rate/100); tax-inclusive is amount × (1 + rate/100). For example, 1,000 JPY becomes 900 JPY at 10% off and 1,100 JPY at 10% tax.
Feedback
Missing a feature, or getting a result that looks wrong? Let us know — we improve our tools based on your feedback.