Find the original value before a percentage increase or decrease
Original Value Before Change
Formula Used:
Original Value = Final Value / (1 + (Percentage / 100))
Calculation Steps:
1. Convert percentage to decimal: 20% = 0.20
2. Add 1 to the decimal: 1 + 0.20 = 1.20
3. Divide final value by this number: 120 / 1.20 = 100
Sale Price: If an item costs $84 after a 30% discount, the original price was $120.
Salary Increase: If your salary is $52,000 after a 4% raise, your original salary was $50,000.
Tax Calculation: If the total with 8% tax is $216, the pre-tax amount was $200.
Reverse percentages help you find the original value before a percentage change was applied. This is useful for sale prices, tax calculations, and salary adjustments.
A frequent error is simply subtracting the percentage from the final value. This doesn't work because percentages are relative to the original amount, not the final amount.
Use reverse percentages to determine pre-tax prices, original prices before discounts, or salaries before raises. It's essential for financial planning and analysis.