Four fifths
4/5 = 0.8 = 80% — decimal and percent
Four fifths is exactly 0.8 as a decimal and 80% as a percentage. Divide 4 by 5 to get 0.8, then multiply that decimal by 100 to get 80%.
Four fifths
Why does 4/5 equal exactly 0.8 and 80%?
Multiply the numerator and denominator by 20: 4/5 = 80/100 = 0.8 = 80%. As a quick check, one fifth is 20%, so four equal fifths total 80%.
- Decimal
- 0.8
- Percent
- 80%
- Mixed number
- 4/5
Calculated locally
Enter two fractions
Exact result
4/5
- Improper fraction
- 4/5
- Mixed number
- 4/5
- Decimal
- 0.8 Terminating decimal
- Percent
- 80% Terminating decimal
Exact formula
4/5 → 4/5Common divisor used to reduce: 1
Exact reference
Common fraction equivalents
Finite decimals are shown in full. An ellipsis marks a repeating value, so the fraction remains the exact reference.
| Fraction | Decimal | Percent | Common use |
|---|---|---|---|
| 1/2 | 0.5 | 50% | Two equal parts |
| 1/3 | 0.(3) | 33.(3)% | Three equal parts |
| 2/3 | 0.(6) | 66.(6)% | Two of three parts |
| 1/4 | 0.25 | 25% | Four equal parts |
| 3/4 | 0.75 | 75% | Three of four parts |
| 1/5 | 0.2 | 20% | Five equal parts |
| 2/5 | 0.4 | 40% | Two of five parts |
| 3/5 | 0.6 | 60% | Three of five parts |
| 4/5 | 0.8 | 80% | Four of five parts |
| 1/8 | 0.125 | 12.5% | Eight equal parts |
| 3/8 | 0.375 | 37.5% | Three of eight parts |
| 5/8 | 0.625 | 62.5% | Five of eight parts |
| 7/8 | 0.875 | 87.5% | Seven of eight parts |