About

The 20% figure is a cornerstone of global commerce. It represents the standard Value Added Tax (VAT) rate in the United Kingdom and several other nations, as well as a popular discount tier in retail marketing. Whether you are a shopper trying to determine the final sale price or a business owner calculating tax-exclusive revenue, accuracy is paramount.

This tool features a dual-mode engine. The standard mode calculates the Net price after a 20% cut. The unique Reverse Mode answers the question: "If this amount is what remains after a 20% reduction, what was the starting figure?" This is particularly useful for reconstructing original prices from discounted receipts.

Formulas

Standard Deduction: To find the price P_final after taking 20% off an original P_orig:

P_final = P_orig × 0.8

Reverse Calculation: To find the Original Price P_orig if you know the Final Price P_final (which represents 80% of the value):

P_orig = P_final0.8

Reference Data

Mode	Input (x)	Operation	Result
Standard (Discount)	100	100 × 0.80	80
Standard (VAT Excl.)	50	50 − 20%	40
Reverse (Find Orig.)	80	80 ÷ 0.80	100
Reverse (Find Orig.)	160	160 ÷ 0.80	200

Frequently Asked Questions

Mathematically, yes: both involve reducing a base number by 20%. However, if you are trying to remove VAT from a gross price (e.g., £120) to find the net, the math is different (dividing by 1.2). This tool specifically handles 20% deductions (discounts), not tax-inclusive reverse calculations.

Use Reverse Mode when you have the after-sale price and want to know how much the item cost originally. For example, if you paid $80 and knew it was '20% off', Reverse Mode tells you the tag price was $100.