Free Online Multi-Buy Discount Calculator
Calculate BOGO, quantity, and tiered multi-buy discounts.
Every second unit is free. With an odd quantity, the last unit is paid in full.
Choose an offer type to see how the discount is applied.
About the Multi-Buy Discount Calculator
Multi-buy promotions are everywhere in retail: buy one get one free, three for two, a percentage off when you reach five units, or a discount once the basket crosses a spending threshold. Each format communicates a different deal and has a different effect on revenue. This calculator applies the selected offer to a unit price and quantity, then shows the subtotal, discount, final price, and effective price per unit so you can compare offers on equal terms.
Buy one get one free is the simplest. Every pair of units contains one free unit, so six units cost the same as three, and five units cost the same as three plus one paid unit. Buy X get Y free generalizes the idea: the offer repeats in groups of X plus Y. With a buy-two-get-one-free offer and seven units, two complete groups apply, giving two free units, and the seventh unit is paid in full. Tier discounts apply a percentage to the entire subtotal once the quantity reaches a threshold. Spend thresholds do the same based on the pre-discount subtotal. The tool does not stack offers; it evaluates one rule at a time.
The effective unit price is the number to watch when comparing promotions. A 15 percent tier discount on a twenty-dollar item yields seventeen dollars per unit across the whole order, while a buy-two-get-one offer yields roughly thirteen dollars and thirty-three cents per unit, but only when the quantity divides evenly. The saving rate shows the discount as a percentage of the subtotal, which makes a BOGO offer easier to compare with a flat percentage. For odd quantities, the final paid unit often weakens the deal, and the effective price reveals that.
This calculator ignores tax, shipping, and payment fees. It also assumes the offer applies to identical units at the same price, which is how most simple multi-buy rules work. If your promotion mixes products or uses a weighted basket, calculate each group separately and add the results. Nothing is uploaded, and the currency selector only changes formatting.
Promotions also shape customer behavior beyond the current order. A buy-two-get-one offer encourages larger baskets but can attract deal-seekers who never pay full price. A tier discount rewards stocking up, which may pull future demand forward and leave a quiet period afterward. Track redemptions, average basket size, and repeat rate during and after the campaign. If the promotion runs continuously, it becomes the real price, and the margin assumption in this calculator should be treated as permanent rather than temporary.
How to use this tool
- Enter the unit price, quantity, and currency.
- Select an offer type and fill in its threshold or ratio.
- Click Calculate final price or change any value.
- Copy the summary for a promotion brief or price tag review.
Frequently asked questions
Can I stack a tier discount and a spend threshold?
No. The tool evaluates one offer at a time. To model stacked promotions, calculate the first discount, then use the result as the subtotal in a second calculation.
Why is one unit still charged on a BOGO order of five?
BOGO pairs units. Four units form two pairs, and the fifth unit has no partner, so it is paid in full.
Does the discount apply before or after tax?
All values are pre-tax. Tax treatment depends on your jurisdiction and is not modeled here.