More Number Tools

Percentage Calculator

Compare two values, apply percentage increases or decreases with compounding, and reverse-calculate wholes from known parts—all in a single, shareable summary.

Compare two values

Understand relative size, percentage difference, and the absolute gap.

Quick comparison
Comparison results
80 vs 120
66.67%

How large Value A is relative to Value B

Difference
-40

-33.33% relative to Value B

Increase from smaller to larger
50.00%

How much the smaller number grows to reach the larger

Category
Value A is lower

Based on absolute comparison

Apply a percentage

Instantly calculate increases, decreases, and compound growth.

Adjustments

Useful for monthly growth, yearly returns, or repeated discounts.

Adjustment results
Amount change
18

12% of 150

Increase
168

Base plus the rate

Decrease
132

Base minus the rate

3× compounded
210.7392

Repeatedly apply the rate

PeriodValue
1168
2188.16
3210.7392

Reverse lookup

Work out the original whole when you only know a part and its percentage.

Find the whole
Reverse lookup results
Whole value
300

45 is 15% of this

Percentage check
15.00%

Consistency check rounding to two decimals

Remainder
255

What's left after removing the known part

How to get the numbers you need

  1. Start with the comparison card to see the raw gap and percent difference between two values.
  2. Use the adjustment slider to model a price increase, discount, or KPI change over multiple periods.
  3. Switch to the reverse lookup when stakeholders give you a part-and-percent combo and you need the original whole.
  4. Copy the summary to drop into updates, Jira issues, or spreadsheets without reformatting.

Where this calculator fits best

Frequently Asked Questions