What is the Percentage Difference from 50 to 45?
From 50 to 45 is a 10% decrease
Step by step
- Difference: 45 − 50 = -5
- Divide by the starting value: -5 ÷ 50 = -0.1
- Multiply by 100: -10%
How the answer is worked out
Percentage change measures a difference against the value you started with. The value went from 50 to 45, a difference of 5. Compared with the starting value of 50, that difference is 10%, so this is a 10% decrease.
The new value is 90% of the old one: for every 100 at the start there are now 90, so 10 out of every 100 have gone.
Why calculate this?
Percentage change compares a new value with an old one regardless of size: price rises, growth, discounts, score changes.
- Sales: a price cut from $50 to $45 is a 10% discount.
- Weight: going from 50 to 45 kilograms is a loss of 10% of the starting weight.
- Results: if a team scores 45 points this season after 50 last season, its total has dropped by 10%.
A quicker way
Find 1% of the starting value: 50 ÷ 100 = 0.5. The difference of 5 is 10 of those steps.
Percentage change is not the same as percentage points. If a rate moves from 50% to 45%, it changes by 5 percentage points, but by 10% relative to where it started.
Check the answer
Work forwards from the start: 50 × (1 − 0.1) = 50 × 0.9 = 45. Getting 45 shows the answer is right.
Rounding
Rounded to a whole number the change is -10, to one decimal place -10.0 and to two decimal places -10.00. Round only at the end: rounding halfway through a calculation can change the last digit.
The formula explained
percentage change = (new value − old value) ÷ old value × 100. A positive result is an increase and a negative result is a decrease. The old value is always the base, which is why the change from A to B and from B to A are different percentages.
Another worked example: 10 to 86
- Difference: 86 − 10 = 76
- Divide by the starting value: 76 ÷ 10 = 7.6
- Multiply by 100: 760%
Why the change back is different
A 10% fall followed by a 10% rise does not bring you back to 50: it gives 49.5. The second percentage is taken of 45, not of 50, so to undo this change you need 11.1111% instead.
Other ways to ask this
The same calculation is often asked in other words. All of these have the answer above:
- Percentage decrease from 50 to 45
- What percent less is 45 than 50?
- 50 to 45 as a percent change
- How much did 50 fall going to 45, in percent?
- Relative change between 50 and 45
Terms used on this page
- Old value: the starting amount, used as the base of the percentage.
- New value: the amount after the change.
- Increase: a positive change: the new value is bigger.
- Percentage point: the plain difference between two rates, not a relative change.
The answer in other forms
| Change | -10% |
|---|---|
| Difference | -5 |
| New ÷ old | 0.9 |
| Direction | decrease |
Related results
| 50 to 43 | From 50 to 43 is a 14% decrease |
| 50 to 44 | From 50 to 44 is a 12% decrease |
| 50 to 46 | From 50 to 46 is a 8% decrease |
| 50 to 47 | From 50 to 47 is a 6% decrease |
| 50 to 55 | From 50 to 55 is a 10% increase |
The other way round: Percentage difference from 45 to 50
Doing it in a spreadsheet
In Excel, Google Sheets or Numbers type =(45-50)/50*100 into any cell. Replace the numbers with cell references (for example A1 and B1) to reuse the formula for a whole column.
Common mistakes
Always divide by the starting value, not the new one. A rise from 40 to 50 is +25%, but the fall from 50 back to 40 is −20%.
Practice examples
| 10 to 86 | Show answerFrom 10 to 86 is a 760% increase |
| 69 to 85 | Show answerFrom 69 to 85 is a 23.1884% increase |
| 69 to 43 | Show answerFrom 69 to 43 is a 37.6812% decrease |
| 96 to 83 | Show answerFrom 96 to 83 is a 13.5417% decrease |
| 78 to 45 | Show answerFrom 78 to 45 is a 42.3077% decrease |
| 43 to 66 | Show answerFrom 43 to 66 is a 53.4884% increase |
| 69 to 55 | Show answerFrom 69 to 55 is a 20.2899% decrease |
| 38 to 34 | Show answerFrom 38 to 34 is a 10.5263% decrease |
| 93 to 15 | Show answerFrom 93 to 15 is a 83.871% decrease |
| 40 to 7 | Show answerFrom 40 to 7 is a 82.5% decrease |
How this answer was calculated
The result is worked out from the numbers in this page's address when the page is opened, using exact arithmetic wherever possible and rounding only for display. Nothing is copied from a printed table. If you think an answer is wrong, please tell us through the contact page and we will check it.
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Questions
What is the Percentage Difference from 50 to 45?
Going from 50 to 45 is a 10% decrease. Formula and steps.
Is going from 50 to 45 an increase or a decrease?
A decrease: the value fell by 5, which is 10% of the starting value.
What is the percentage change from 45 back to 50?
11.1111%. It is a different number because the starting value is now 45, not 50.
What is the percentage difference between 50 and 45?
When neither value is the starting point, use the average as the base: 5 ÷ 47.5 × 100 = 10.5263%. That is the symmetric percentage difference.
How do I calculate percentage change in Excel or Google Sheets?
Put the old value in A1 and the new value in B1, then type =(B1-A1)/A1 and format the cell as a percentage. For these numbers it shows -10%.