Calculate the missing value in a reverse inflation calculator by entering current price, inflation rate, and initial price before inflation.

Reverse Inflation Calculator

Enter any 2 values to calculate the missing variable

Reverse Inflation Formula

The reverse inflation calculation is based on the relationship between an initial price, an inflation rate, and the current price after inflation.

CP = IP * (1 + IR / 100)
IP = CP / (1 + IR / 100)
IR = ((CP / IP) - 1) * 100
  • CP = current price after inflation
  • IP = initial price before inflation
  • IR = inflation rate as a percentage

The calculator can solve for any one missing value when you enter the other two values.

  • To find current price: enter the initial price and inflation rate.
  • To find initial price before inflation: enter the current price and inflation rate.
  • To find inflation rate: enter the initial price and current price.

Common Inflation Rate Effects

This table shows how different inflation rates affect an item that originally cost $100.

Inflation Rate Initial Price Current Price Increase
2% $100.00 $102.00 $2.00
5% $100.00 $105.00 $5.00
10% $100.00 $110.00 $10.00
25% $100.00 $125.00 $25.00

Reverse Inflation Examples

Example 1: Find the initial price before inflation

You know the current price is $120 and the inflation rate is 20%.

IP = 120 / (1 + 20 / 100)
IP = 120 / 1.20 = 100

The initial price before inflation was $100.00.

Example 2: Find the inflation rate

You know the initial price was $80 and the current price is $92.

IR = ((92 / 80) - 1) * 100
IR = (1.15 - 1) * 100 = 15

The inflation rate was 15%.

Reverse Inflation Calculator FAQ

What does reverse inflation mean?

Reverse inflation means working backward from a price after inflation to find the earlier price before inflation. For example, if an item costs $150 now after 25% inflation, reverse inflation can show that the original price was $120.

How do you calculate the original price before inflation?

Divide the current price by 1 plus the inflation rate written as a decimal. For example, with a current price of $210 and inflation of 5%, calculate $210 / 1.05. The original price was $200.

Can the inflation rate be negative?

Yes. A negative inflation rate means the price decreased instead of increased. This is often called deflation. For example, if a price falls from $100 to $90, the inflation rate is -10%.