Percent change from 100 to 80
100 → 80−20%
Going from 100 to 80 is a decrease of 20%.
Try other numbers
Change from 100 to 80: -20%
Step by step
- 1Find the difference: 80 − 100 = −20.
- 2Divide by the starting value: −20 ÷ 100 = −0.2.
- 3Multiply by 100: −0.2 × 100 = −20%.
Other ways to get there
- Why the order matters
- Percent change always divides by the starting value. Going back from 80 to 100 is +25%, not −20%.
- Percent difference
- If neither value is the "start", use the percent difference: |80 − 100| ÷ average (90) × 100 ≈ 22.22%.
Changes from 100
- 100 → 50−50%
- 100 → 75−25%
- 100 → 90−10%
- 100 → 110+10%
- 100 → 125+25%
- 100 → 150+50%
- 100 → 200+100%
Frequently asked questions
What is the percentage decrease from 100 to 80?
−20%. The difference −20 divided by 100, times 100.
What is the percent change from 80 to 100?
+25%, because this time the change is divided by 80.
What is the percent difference between 100 and 80?
≈ 22.22%. The percent difference compares the gap with the average of both values.