Percentage Off Calculator Guide: Calculate Discounts & Sale Prices

Whether you're shopping in the sales, comparing deals, or working out business discounts, knowing how to calculate percentage off is an essential skill. This guide explains the formulas and provides quick reference tables for common discounts.

How to Calculate Percentage Off

Quick Multipliers for Common Discounts

Multiply the original price by these numbers to get the sale price directly:

Common Discount Scenarios

Discount Table: Various Prices

Finding the Original Discount Percentage

If you know the original price and sale price, you can calculate what percentage off was applied:

Finding the Original Price

If you know the sale price and discount percentage, you can work backwards:

Successive Discounts

When multiple discounts are applied one after another, they don't simply add up!

Buy One Get One (BOGOF) Deals

Sales Tax and Discounts

In the UK, displayed prices usually include VAT, so discounts are straightforward. But if you're calculating for business:

Mental Maths Shortcuts

• 1% off: Divide by 100
• 5% off: Find 10%, halve it
• 10% off: Move decimal one place left
• 15% off: 10% + 5%
• 20% off: 10% × 2
• 25% off: Divide by 4
• 33% off: Divide by 3
• 50% off: Divide by 2
• 66% off: Divide by 3, keep the third
• 75% off: Divide by 4, keep the quarter

Real-World Examples

Comparing Deals

When comparing deals, convert everything to the same basis:

Conclusion

Key points to remember:

• Multiply by (1 - discount/100) to find sale price directly
• 10% is the building block for mental maths
• Successive discounts don't simply add up
• BOGOF = 50% off when buying 2
• Always calculate the actual savings to compare deals

With these techniques, you'll never be confused by sale prices again!

UK VAT and Percentage Calculations

Value Added Tax (VAT) is the most common percentage calculation that UK consumers and businesses encounter daily. The standard UK VAT rate is 20%, applied to most goods and services. A reduced rate of 5% applies to certain items such as domestic energy, children's car seats, and some energy-saving installations. A zero rate (0%) applies to most food, children's clothing, books, and newspapers. Understanding how VAT interacts with discounts is important for both shoppers and business owners.

When a UK retailer advertises a price, it must by law include VAT for consumer sales. This means the discount percentage shown in a sale is applied to the VAT-inclusive price. However, for business-to-business transactions, prices are often quoted excluding VAT. If you see a trade price of 200 pounds plus VAT with a 15% discount, the calculation works as follows: apply the 15% discount first (200 x 0.85 = 170 pounds), then add 20% VAT (170 x 1.20 = 204 pounds). The order matters, though in this case the final result is the same either way because both operations are simple multiplication.

To extract the VAT from a VAT-inclusive price, divide by 1.20 (for the standard rate). For example, if an item costs 60 pounds including VAT, the pre-VAT price is 60 divided by 1.20, which equals 50 pounds, and the VAT portion is 10 pounds. This is useful when filing VAT returns or when you need to understand the true cost of a discounted item before tax.

UK Sale Season Calendar

British retailers follow a predictable pattern of sales events throughout the year. Knowing when these occur can help you plan purchases and evaluate whether a discount truly represents good value.

• January Sales: The traditional post-Christmas clearance begins on Boxing Day (26 December) or even Christmas Day online, running through most of January. Discounts typically range from 30% to 70% off winter stock.
• Easter Sales: A smaller sale period around the Easter bank holiday weekend, with discounts usually between 15% and 30%.
• Summer Sales: Beginning in late June or early July and running through August, these clear spring and summer stock with reductions of 20% to 60%.
• Black Friday and Cyber Monday: Adopted from the United States, this late November event has become one of the largest sale periods in the UK. Discounts can be significant, but consumer groups such as Which? have found that some items are available at the same or lower prices at other times of the year.
• Singles Day (11 November): Growing in popularity with online retailers, particularly those with connections to Chinese marketplaces.
• Amazon Prime Day: Typically held in July, exclusively for Amazon Prime members, with percentage discounts across thousands of product categories.

Consumer Rights on Discounted Goods in the UK

Under the Consumer Rights Act 2015, your rights are the same whether you buy an item at full price or during a sale. If goods are faulty, not as described, or not fit for purpose, you are entitled to a refund, repair, or replacement regardless of any discount applied. Retailers cannot use signs stating "no refunds on sale items" to override your statutory rights.

However, there is an important distinction: if you were made aware of a fault before purchasing (for example, a garment clearly marked as having a minor defect and discounted accordingly), you cannot later return it for that specific fault. Your rights still apply to any other faults that were not disclosed at the point of sale.

The Chartered Trading Standards Institute also monitors reference pricing, which is the practice of showing a "was" price alongside the sale price. Under the Consumer Protection from Unfair Trading Regulations 2008, the reference price must be genuine. The item must have been offered at the higher price for a reasonable period before the discount. If a retailer inflates the "was" price to make the discount appear larger than it truly is, this can constitute a misleading commercial practice.

Frequently Asked Questions

Do I have to pay VAT on sale items in the UK?

Yes. VAT is applied to the sale price, not the original price. Since UK consumer prices already include VAT, the discounted price you see on the shelf or online is the final amount you pay. There is no additional VAT charged at the checkout for consumer purchases. For businesses reclaiming VAT, the reclaimable amount is based on the actual price paid after the discount, not the original pre-sale price.

Can a UK retailer refuse to refund a sale item?

A retailer cannot refuse a refund for a faulty sale item. Under the Consumer Rights Act 2015, you have 30 days from purchase to return faulty goods for a full refund, whether the item was bought at full price or at a discount. After 30 days, the retailer may offer a repair or replacement instead. However, if you simply change your mind about a sale purchase made in-store, the retailer is not legally required to offer a refund, though many do so as a goodwill gesture under their own returns policy.

How can I tell if a sale discount is genuine in the UK?

Check the item's price history using tools such as CamelCamelCamel for Amazon products or PriceRunner for broader comparisons. Trading Standards guidance suggests that a "was" price should have been the prevailing selling price for at least 28 consecutive days in the previous six months. If a product's "was" price was only in effect for a very brief period or was only offered at a single store, the discount claim may be misleading. You can report suspected misleading pricing to your local Trading Standards office through the Citizens Advice consumer helpline.