Calculate percentage increase and decrease, X% of an amount and what percentage one number is of another. Add or subtract a percentage or VAT and work back to the original amount, with the formula and working shown.
Fill in the fields and press Calculate to see the result.
The percentage calculator works out percentage increase and decrease, finds X% of an amount, shows what percentage one number is of another, adds or subtracts a percentage, works back to the amount before a percentage change, and adds or removes 25% VAT (the Danish rate). Every calculation shows the formula and the working, so you can see how the result was reached.
Subtract the old value from the new one, divide by the old value and multiply by 100. A positive result is an increase, a negative one a decrease. This is the % change tab.
(new value − old value) ÷ old value × 100
Example: (33,600 − 32,000) ÷ 32,000 × 100 = 5% increase
The order matters: you always divide by the value you start from. If a salary goes from 33,600 back down to 32,000, the decrease is 4.76% — not 5%.
Divide the percentage by 100 and multiply by the amount. This is the Percent of tab. To add the percentage to the amount or take it off, use Add % or Subtract %.
percentage ÷ 100 × amount
Example: 5 ÷ 100 × 2,000,000 = 100,000
Divide the part by the whole and multiply by 100. This is the What % tab. It answers, for example, what share of a salary goes on rent, or what percentage of the hours is overtime.
part ÷ whole × 100
Example: 450 ÷ 1,800 × 100 = 25%
If you only know the amount after a markup or discount, divide by 1 plus the percentage as a decimal. In the Find original tab you enter the amount and 100 plus the percentage: 125 after a 25% markup, 80 after a 20% discount. If you just enter 25, you get the number the amount is 25% of — four times as much.
new value ÷ (1 + percentage ÷ 100)
Example: 6,250 ÷ 1.25 = 5,000
A price without VAT has its own tab, Remove VAT, which also shows the VAT amount separately.
What is 12% pension on a base salary of DKK 35,000?
(12 ÷ 100) × 35,000 = DKK 4,200
Pay goes up from DKK 32,000 to DKK 33,600 — what percentage is the increase? If you only know the amounts before and after tax, first work them out with the salary converter.
((33,600 − 32,000) ÷ 32,000) × 100 = 5%
An invoice is for DKK 6,250 incl. VAT. What is the amount excl. VAT? Use the Remove VAT tab.
6,250 ÷ 1.25 = DKK 5,000
A service costs DKK 8,000 excl. VAT. What is the total price with 25% VAT (the Danish rate)?
8,000 × 1.25 = DKK 10,000
A percentage increase and percentage points are not the same thing. A supplement that goes from 10% to 12% has risen 2 percentage points, but 20% in relative terms.
In pay negotiations, always convert the percentage increase into kroner — it gives a more concrete basis than percentages alone.
Use Find original to work out your pay before a supplement if you only know the final amount: enter 100 plus the supplement, e.g. 110 for a 10% supplement.
A pay rise in percent doesn’t tell you whether you can actually buy more. The real wage calculator deducts price inflation.
Content last reviewed October 2026.