Percentage Calculator
Calculate percentages in four modes: X% of a value, percentage change between two numbers, percent increase or decrease, and how much a value represents as a percentage of a total.
How it works
Choose one of the four modes: (1) X% of a value computes the percentage over the base; (2) percentage change measures how much a value moved relative to the initial one; (3) increase or decrease applies the percentage to the value; (4) find the original recovers the base from an already percentage-adjusted value. All results use precise rounding rules.
Facts about the Percentage Calculator
- Computes X% of a value with decimal precision.
- Measures the percentage change between two values.
- Applies percent increase and decrease.
- Recovers the original value from a percentage.
Official references
Check the official references to understand how percentages work:
- IBGE Educa — What if Brazil had 100 people?: Official IBGE content explaining the concept of percentage (whole = 100%).
- Goiânia Municipal Education Department — Percentage and problem situations: Official material (BNCC EF09MA05-B) on percentages, successive percentages and percentage rates.
- MEC — National Common Curricular Base (Mathematics: percentage): Official BNCC document with the progression of percentage skills from 5th to 9th grade (EF05MA06 to EF09MA05).