Percentage Decrease in Excel and Google Sheets

Direct answer

With the original value in A2 and new value in B2, use =(A2-B2)/A2 and format the result cell as a percentage.

Formula and method

=(A2-B2)/A2

The calculation keeps full precision through the formula and rounds only the displayed answer.

Step-by-step calculation

1. Put the original value in A2 and the new value in B2.
2. Enter =(A2-B2)/A2 in C2.
3. Apply percentage formatting; do not multiply by 100 as well.
4. Use =IF(A2=0,NA(),(A2-B2)/A2) to expose an undefined baseline.

Worked examples

Decrease result

A2=250 and B2=200 returns 0.20, displayed as 20%.

New amount after rate

If A2 is the original and B2 contains 15%, use =A2*(1-B2).

Reverse

If A2 is the final and B2 is 15%, use =A2/(1-B2).

Interpretation and edge cases

• Percentage formatting already scales 0.20 to 20%; multiplying by 100 can create 2,000%.
• Avoid IFERROR that hides a zero-baseline issue without explanation.
• Store unrounded values and format the display separately.

Related tools and guides

• Percentage Decrease Calculator
• Reverse Percentage Decrease
• Successive Percentage Decreases

Frequently asked questions

Sources and transparency

• Microsoft Support — Calculate percentages
• Google Docs Editors Help — Add formulas and functions

The formulas and examples were evidence-checked on 2026-09-10. This is educational mathematical content. It does not replace a field-specific standard, accounting policy, laboratory method, contractual definition or professional judgment.