DigiKitAdvanced Discount Calculator - DigiKitApp
Calculate discount and tax together.
When should you use this?
Use this when you need to calculate a discounted price, or the combined effect of multiple discounts applied in sequence (20% plus an additional 10%, say).
When shouldn't you use this?
Don't assume stacked discounts simply add up; 20% plus 10% doesn't equal a 30% discount overall, it comes out closer to 28%, which is exactly why using the tool beats estimating by hand.
Step-by-step
- Enter the original, undiscounted price in the Price field. Just the number, no currency symbol.
- Enter the discount rate in Discount %, for example 20 for twenty percent.
- If the price excludes tax and you want the final amount with tax, fill in Tax % (optional). If tax is already included, leave it blank.
- Click Run and read the discounted price and, if you added tax, the total you'll pay.
Example
A supplier quotes you 1000 before tax, offers a 20% discount, and the invoice will add 20% tax. Enter 1000, 20 and 20. The discounted price is 800, and the total with tax comes to 960. Because percentages are applied by multiplication, the order doesn't matter: 1000 × 0.80 × 1.20 and 1000 × 1.20 × 0.80 both give 960.
The same example shows that equal rates don't cancel out. A 20% discount followed by 20% tax doesn't take you back to the starting price. You end up at 960, not 1000.
How is a discount calculated?
Discounted price = Price × (1 − discount rate). For example, 25% off an 800 item: 800 × 0.75 = 600; the discount amount is 200. Successive discounts do not add up: 20% followed by 10% is not 30% but 1 − 0.8 × 0.9 = 28%.
What to watch in discount maths
- In offers such as “50% + 20%” the total discount is 60%, not 70% (0.5 × 0.8 = 0.4).
- Do not mix prices with and without VAT; know which price the discount applies to.
- When comparing unit prices, take the pack size into account.
- Beware of discounts shown against an artificially raised old price; compare with the lowest price of recent weeks.
Things to keep in mind
- Consumer prices in many countries, including Turkey and across the EU, already include VAT. Adding tax to those prices again gives a total higher than what you'll actually pay.
- VAT and sales tax rates vary by product and change over time. For invoices, check the current rate with your tax authority.
- Store promotions like an extra discount at checkout may apply to a different base amount. Read the promotion terms.
- Results with cents can differ slightly because of rounding. For bookkeeping, go by the figure on the invoice.
Frequently asked questions
How accurate are the results?
Calculations use standard mathematical formulas; for official purposes (tax, loan applications, etc.) we recommend confirming current rates with the relevant institution.
Are the numbers I enter saved?
No, no numbers are sent to a server; the calculation happens entirely in your browser.
Can I use this on mobile?
Yes, the tool works smoothly on all screen sizes.