How to calculate a discount and its VAT
The tool above works as you type. The discount comes off first and the VAT is charged on what is left — which is what the tax authorities themselves require.
Pick the country
The currency and VAT rate follow: 15% in Saudi riyals, 5% in UAE dirhams, 10% in Bahraini dinars, 5% in Omani rials. Kuwait and Qatar have not implemented VAT, so the tool becomes a plain discount calculator there.
Say whether the price includes VAT
If the figure in front of you is a shelf price or an advertised price it almost certainly includes VAT — in the UAE the law requires it. Choose “including VAT” and the tool extracts the tax first, then applies the discount to the net amount.
Enter the discount as a percentage or an amount
Type 20 for 20% off, or switch to a fixed amount and enter the value directly. If you have two or three successive discounts, add a row for each.
Read all five figures, then copy them
You get the list price, the discount, the taxable amount, the VAT and the total — plus what the customer actually saves. Copy gives you the lines ready to paste into WhatsApp, an email or a spreadsheet cell, in Latin digits that accounting software can read.
The discount comes off before the VAT, not after
This is not a matter of opinion. The UAE’s Federal Decree-Law No. (8) of 2017 says at Article (39) that “when discounts are made before or after the Date of Supply … the value of the supply shall be reduced in proportion to such discounts”. In Saudi Arabia, ZATCA’s Electronic Invoice XML Implementation Standard defines the VAT category taxable amount as the sum of the line net amounts minus the allowances. In Oman, Article (31) of the VAT Law excludes “deductions” from the taxable value.
The practical consequence is the same in all three markets: take the discount off, then charge VAT on what remains. A Saudi example at 15% — SAR 1,000 with 10% off gives a discount of 100, a taxable amount of 900, VAT of 135 and a total of 1,035. Charging VAT on the undiscounted 1,000 would produce 150, which is SAR 15 of tax that is not owed.
We examined thirteen discount calculators. One of them has a tax field at all. The Arabic publishers that explain the rule correctly in their articles — including well-known accounting platforms — then hand the reader a calculator without the field they just described.
Discounting a VAT-inclusive price: the case everyone skips
Article (38) of the same UAE decree-law states that “for Taxable Supplies, the advertised price shall include the Tax”. So the number on the shelf, in the catalogue and in most Gulf point-of-sale systems is an inclusive one. When a shop says “20% off”, it is 20% off an inclusive figure, not off a net amount.
Every tool we examined starts from a net price and adds tax afterwards. This one accepts both. Choose “including VAT” and it extracts the tax first using the correct extraction formula, applies the discount to the net amount, then recomputes the VAT on what is left.
An example: an advertised SAR 1,150 including 15% VAT, with 20% off. The amount before VAT is 1,000, the discount 200, the taxable amount 800, the VAT 120 and the total 920. Note that the customer actually saves 230, not 200 — because they also avoid the VAT on the discounted portion. Those are two different numbers, and the tool shows both, because one belongs on the invoice and the other belongs in the customer’s pocket.
Why Bahrain, Oman and Kuwait show three decimals
The Bahraini dinar, Omani rial and Kuwaiti dinar are 1000-minor-unit currencies, not 100: a dinar is 1,000 fils and a rial is 1,000 baisa. Their amounts are written to three decimal places.
The only Arabic calculator we found that puts a discount and a tax rate in the same form offers a decimal-places setting of 0, 1 or 2. It cannot express a Bahraini fils or an Omani baisa at all — not as a default, but as a ceiling.
This tool uses each currency’s own precision. A Bahraini example: BHD 12.345 with 10% off and 10% VAT gives a discount of 1.235, a taxable amount of 11.110, VAT of 1.111 and a total of 12.221. Rounded to two decimals, all five figures are wrong.
20% then 10% is not 30%
Successive discounts multiply rather than add: the second comes off the price the first one left, not off the original. SAR 1,000 with 20% off becomes 800, then 10% off that is 720 — an effective discount of 28%, not 30%. For two discounts a and b the combined rate is a + b − (a × b ÷ 100).
The rule is well known and appears in the FAQs of several Arabic sites, but none of the Arabic calculators compute it — they all offer a single discount field. Here you can add up to three successive discounts, and the tool shows each one separately and then the effective combined rate.
There is an accounting reason to chain them rather than combine them, too. ZATCA records each discount as its own allowance on the e-invoice, rounded separately. Computing the chain step by step keeps the figures on screen identical to the ones that will appear on your invoice.
The figures always reconcile
Three identities hold for every amount, discount, rate and currency: list price minus discount equals the taxable amount; taxable amount plus VAT equals the total; and advertised price minus what you saved equals what you pay.
They hold because each figure is derived from the one before it rather than computed independently. The discount is rounded first — which is exactly what ZATCA’s e-invoicing standard requires — then subtracted; then the VAT is rounded; then the total follows. Adding and subtracting already-rounded figures introduces no drift, so the column cannot fail to add up.
The familiar shortcut “price × (1 − discount rate)” is not the same function once rounding is involved: it can print a discount amount different from the one it actually subtracted. The difference is usually a single halala — and a single halala is precisely what stops a journal entry balancing.
This calculator does not decide whether your discount qualifies
It is an arithmetic tool: it applies the discount and rate you choose to the amount you enter. Whether a particular discount actually reduces the value of a supply is a legal question about a transaction, not a mathematical one.
The UAE Executive Regulation (Cabinet Decision No. 52 of 2017, Article 28) sets two conditions: the customer must have benefited from the reduction in price, and the supplier must have funded the discount. Oman’s law refers the detail of “deductions” to its Regulations. Vouchers are treated differently again.
So there is no promise here to work out your tax position. Choose what applies to your transaction, and we will make sure the arithmetic is right to the last fils.
Frequently asked questions
Is VAT calculated before or after a discount?
After. The discount comes off first and VAT is charged on the discounted amount. UAE Federal Decree-Law No. (8) of 2017, Article (39), requires the value of the supply to be reduced in proportion to the discount; ZATCA’s Electronic Invoice XML Implementation Standard defines the taxable amount as line nets minus allowances; and Article (31) of Oman’s VAT Law excludes deductions from the taxable value.
How do I calculate the price after a discount?
Multiply the price by the discount percentage and divide by 100 to get the discount amount, then subtract it. SAR 1,000 with 20% off gives a discount of 200 and a price after discount of 800. If VAT applies, charge it on the 800, not the 1,000.
How do I find the price before a discount?
Divide the discounted price by (1 − the discount rate). A price of 150 after 25% off was 150 ÷ 0.75 = 200 before the discount. Choose the “price before discount” mode in the tool above and it works it out for you.
How do I work out the discount percentage between two prices?
Subtract the discounted price from the original, divide by the original, and multiply by 100. From 200 to 150 is a discount of 50, and 50 ÷ 200 × 100 = 25%.
20% off then another 10% off — what is the total discount?
28%, not 30%. The second discount applies to the price the first one left: 1,000 becomes 800, then 720. For two successive discounts a and b the combined rate is a + b − (a × b ÷ 100).
The shop price includes VAT — how do I discount it?
Extract the VAT first, apply the discount to the net amount, then recompute the VAT on what is left. Choose “including VAT” in the tool above and it does this automatically. Note that what you save as a customer is more than the discount recorded on the invoice, because you also avoid the VAT on the discounted portion.
Why does the result show three decimal places?
Because the Bahraini dinar, Omani rial and Kuwaiti dinar are 1000-minor-unit currencies: a fils is one thousandth of a dinar and a baisa one thousandth of a rial. Rounding to two decimals loses fils and baisa, and produces figures that will not match books kept to the fils.
Can I use it without VAT?
Yes. Pick Kuwait or Qatar, or set the rate to zero, and the tool becomes a plain discount calculator showing just the price, the discount and the final price. Neither Kuwait nor Qatar had implemented VAT as at the last review of this page.