reverse percentage calculator

🔁 Reverse Percentage Calculator – Find the Original Value Before a Percentage Change

A Reverse Percentage Calculator helps you calculate the original amount before a known percentage increase or decrease was applied to get the final value. It’s useful for finding pre-tax prices, discounted prices, or original salaries before hikes.

🧠 What You Know:

• The final value after a percentage change
• The percentage of increase or decrease
  You want to work backwards to get the original value.

🧮 Formulas for Reverse Percentage

🔼 For Percentage Increase:

Original Value = Final Value ÷ (1 + Percentage ÷ 100)

Example:
Final Price = ₹120
Increase = 20%

→ Original Price = ₹120 ÷ (1 + 20 ÷ 100)
→ Original Price = ₹120 ÷ 1.20
→ ₹100

🔽 For Percentage Decrease:

Original Value = Final Value ÷ (1 − Percentage ÷ 100)

Example:
Final Price = ₹80
Discount = 20%

→ Original Price = ₹80 ÷ (1 − 20 ÷ 100)
→ Original Price = ₹80 ÷ 0.80
→ ₹100

📌 When to Use It

Use a reverse percentage calculator when you:

• Know the final value after a discount or markup
• Want to find the original price before tax (e.g., reverse GST or VAT)
• Back-calculate original salaries or costs before raises or price hikes
• Analyze historical prices after inflation

❗ Common Mistakes to Avoid

• Don’t subtract or add the percentage directly from the final value — always divide as shown above
• Make sure to use decimal form of percentage (e.g., 20% = 20 ÷ 100 = 0.20)
• If the percentage change is unknown, this formula won’t work — you need a percent difference calculator

🔍 Trending FAQs Based on User Searches

1. How to find the original price before a 25% increase?

Use:
→ Original = Final ÷ 1.25

2. How do I reverse a 15% discount?

Use:
→ Original = Final ÷ 0.85

3. Can this be used for tax/VAT calculations?

Yes! Use reverse percentage to calculate base price before tax:

• GST 18% → divide by 1.18
• VAT 5% → divide by 1.05

4. What is the formula to find original salary before increment?

If someone received a 10% hike and now earns ₹55,000:
→ Original Salary = ₹55,000 ÷ 1.10
→ ₹50,000

5. Where is reverse percentage used in real life?

• Retail (price before discount)
• Tax calculation (amount before GST/VAT)
• Finance (base investment before gain)
• Salary audits
• Budget planning