Calculate Number Before Percentage Decrease

How to calculate the number before a percentage decrease

To find the original number before a percentage decrease, you can reverse the calculation. Here's a step-by-step guide on how to do it.

Step 1: Understand the Percentage Decrease

Percentage decrease tells you how much the original number has been reduced by a certain percentage. For example, if a number decreases by 20%, you know that the final number is 80% of the original.

Step 2: Gather Your Numbers

You need two numbers: the final number (after the decrease) and the percentage of decrease. For example:

After: 80 (the number after the decrease)
Percentage Decrease: 20%

Step 3: Convert the Percentage Decrease to a Decimal

Subtract the percentage decrease from 100 to get the percentage of the original number remaining. Then convert that percentage into a decimal. For example:

Percentage remaining=100% - 20%=80%

As a decimal: 80%=0.80

Step 4: Calculate the Original Number

To find the original number, divide the final number by the decimal from Step 3:

Original Number=Final Number / Decimal

For this example: Original Number=80 / 0.80=100

Step 5: Verify Your Result

You can verify the calculation by checking if the original number minus the percentage decrease gives you the final number:

Original Number - (20% of Original Number)=Final Number

100 - (20% of 100)=80

Let's Recap:

Understand the Percentage Decrease: Know how much the number decreased.
Gather Your Numbers: After the decrease and the percentage decrease.
Convert to Decimal: Subtract the percentage decrease from 100 and convert to a decimal.
Calculate the Original Number: Divide the final number by the decimal.
Verify the Result: Check if subtracting the percentage decrease from the original gives the final number.

Calculate number before percentage decrease in Excel or Google Sheets

Formula is =A2/(1-B2/100), where A2 is the "After" number, and B2 is the "Percentage".

After: This column represents the number after the percentage decrease.
Before: This column represents the number before the percentage decrease.
%: This column displays the percentage by which the initial number was decreased.

Popular Calculations to Find the Number Before Percentage Decrease

1. Original Price Before Discount

Scenario: After a 25% discount, the price of a jacket is $75. What was the original price?

Calculation: Find the original price before a 25% decrease.

Let X be the original price. The discounted price is 75% of the original price.

$75=X × (1 - 0.25)

$75=X × 0.75

X=$75 / 0.75=$100

Result: The original price of the jacket was $100.

2. Pre-Tax Price Before Tax

Scenario: A meal costs $120 after including a 10% tax. What was the price before tax?

Calculation: Find the pre-tax price before a 10% increase.

Let X be the price before tax. The final price is 110% of the pre-tax price.

$120=X × (1 + 0.10)

$120=X × 1.10

X=$120 / 1.10=$109.09

Result: The price before tax was approximately $109.09.

3. Salary Before Deduction

Scenario: Your salary after a 15% deduction is $2,550. What was your salary before the deduction?

Calculation: Find the salary before a 15% decrease.

Let X be the original salary. The current salary is 85% of the original salary.

$2,550=X × (1 - 0.15)

$2,550=X × 0.85

X=$2,550 / 0.85=$3,000

Result: The salary before the deduction was $3,000.

4. Value Before Depreciation

Scenario: An asset is worth $700 after a 20% depreciation. What was its original value?

Calculation: Find the value before a 20% decrease.

Let X be the original value. The depreciated value is 80% of the original value.

$700=X × (1 - 0.20)

$700=X × 0.80

X=$700 / 0.80=$875

Result: The value before depreciation was $875.

5. Tuition Fee Before Discount

Scenario: A tuition fee of $900 is the result after a 12% discount. What was the original fee?

Calculation: Find the original tuition fee before a 12% decrease.

Let X be the original fee. The discounted fee is 88% of the original fee.

$900=X × (1 - 0.12)

$900=X × 0.88

X=$900 / 0.88=$1,022.73

Result: The original tuition fee was approximately $1,022.73.