Volume Discount Calculator

A volume discount lowers the unit price as the quantity ordered increases, through a table of tiers (minimum quantity and unit price). This calculator applies that table to one order and shows its revenue, average unit price and contribution after variable costs. Sales teams, distributors and e-commerce managers use it to design or check a price grid, answer a quote request and see whether a larger order actually leaves more money to cover fixed costs. It works on one order at a time, not on annual sales.

In all-units mode, the whole order is priced at the unit price of the highest tier the quantity reaches: revenue = quantity × that tier’s price. In progressive mode, each band of units is priced at its own tier: the units up to the next threshold pay the first price, the following units pay the second price, and so on; revenue is the sum of units in each band × that band’s price.

Order contribution = revenue − quantity × variable cost per unit. The variable cost is the cost of one more unit sold: product cost, fulfillment, payment fees, commissions paid per unit. The calculator also shows the average unit price (revenue ÷ quantity), the contribution as a percentage of revenue, and the same order calculated in the other mode for comparison.

Tiers are rows of minimum quantity and unit price. The first tier must start at 1 and each minimum must be strictly higher than the previous one, so bands never overlap. All prices are in one currency and excluding VAT.

What each term means

Tier mode

All-units price or progressive per-band prices.

Where to find it: Choose how your grid is meant to work: all units at the reached tier price, or progressive bands. Check your price list or contract wording; the two give different bills for the same quantity.

Units ordered

Number of units in the order.

Where to find it: Number of units in the order you are pricing, as a whole number of at least 1.

Variable cost per unit

Costs that change with each sale, such as fulfillment and transaction fees.

Where to find it: Cost that each additional unit adds: purchase or production cost plus per-unit fulfillment, packaging, payment fees and commissions. Exclude fixed costs such as rent or salaries.

Tier minimums

Minimum quantity at which each tier becomes applicable. The first tier starts at 1.

Where to find it: The quantity from which each tier applies, taken from your price grid. The first row must be 1; following rows must increase strictly (for example 1, 50, 200).

Tier unit prices

Price offered at each volume tier.

Where to find it: The unit price excluding VAT offered at each tier. Prices usually decrease as tiers rise, but the calculator accepts any non-negative value so you can test alternatives.

Order revenue

Revenue of the order under the selected tier mode.

Revenue with the other tier mode

Same order priced with the other tier mode, for comparison.

Order contribution

Order revenue minus quantity × variable cost per unit.

Hypothetical example: a price grid of 10 per unit from 1 unit, 9 from 50 units and 8 from 200 units; an order of 100 units; a variable cost of 6 per unit.

1. Order revenue100 × 9 = 900
2. Order contribution900 − 100 × 6 = 300

Order contribution = 300

All-units mode: 100 units reach the 50-unit tier, so revenue = 100 × 9 = 900 and contribution = 900 − 100 × 6 = 300. Progressive mode: 49 units × 10 = 490 plus 51 units × 9 = 459, so revenue = 949 and contribution = 949 − 600 = 349. If the variable cost rose to 7, contribution would fall to 200 in all-units mode and 249 in progressive mode, since each unit costs 1 more.

Hypothetical numbers, used to show the calculation. Not real company data.

Use it when you build or revise a volume price grid, when a customer asks for a quote at a quantity near a threshold, or when a sales representative wants to offer the next tier early to close an order.

It is also useful to settle a disagreement about how a grid should be read. Many price lists do not state whether a lower tier price applies to every unit or only to units above the threshold, and the difference on a single order can be substantial.

Run it at several quantities, especially just below and just above each threshold, to see whether contribution grows smoothly with volume or drops at certain points.

A volume discount is meant to trade a lower unit price for more units. That trade only works if the extra units bring more contribution than the price reduction removes from the units you would have sold anyway. With an all-units grid, crossing a threshold reprices every unit in the order, not just the additional ones.

This creates a cliff. In the example grid, 49 units cost 49 × 10 = 490, but 50 units cost 50 × 9 = 450: ordering one more unit lowers the bill by 40. Any order from 46 to 49 units costs the customer more than 50 units, so informed buyers jump to the next tier and your contribution on those orders drops. The same happens below 200 units: 199 × 9 = 1,791 but 200 × 8 = 1,600.

Progressive bands avoid the cliff because only units beyond a threshold get the lower price; revenue never falls when quantity rises. All-units grids can still be sound, but thresholds and prices need to be designed together, and the chart of revenue and contribution against quantity is the quickest way to spot drops. Also check that the deepest tier still leaves a positive contribution per unit after all variable costs.

Read contribution, not revenue. Two grids can produce the same revenue for an order while leaving very different contribution if the variable cost per unit is high relative to the price.

On the chart, a revenue line that steps down as quantity increases signals an all-units cliff. A contribution line that flattens or falls as tiers deepen means the discount is consuming the benefit of volume.

The comparison with the other mode shows how much the tier model alone changes the bill. A large gap means the wording of your price list matters as much as the prices themselves.

Practical levers

• State the tier model explicitly on price lists, quotes and contracts.
• Move all-units thresholds or prices so that the bill never drops when a customer adds units, or switch to progressive bands.
• Check the unit contribution of the lowest tier price against the full variable cost, including fulfillment and payment fees.
• Tie deeper tiers to real cost savings (fewer shipments, longer commitments) rather than to quantity alone.
• Review whether customers actually order more after a tier is introduced, or simply get the lower price on orders they would have placed anyway.

Common mistakes

• Leaving the tier model ambiguous, so sales and customers calculate different bills.
• Pricing a progressive grid as if it were all-units, or the reverse.
• Overlapping or unsorted thresholds, or a first tier that does not start at 1.
• Using a variable cost that ignores fulfillment, payment fees or commissions.
• Judging a grid on revenue growth without looking at contribution per order.
• Mixing currencies or prices including and excluding VAT in one grid.

Scenario comparison

The scenarios move the order quantity by ±20 % (rounded to whole units), the variable cost by ±5 % and every tier price by ±5 %. They are illustrative sensitivities, not forecasts of customer behaviour.

Because thresholds create steps, a 20 % change in quantity can cross a tier and change the result more than proportionally. If a scenario looks surprising, check which tier the new quantity falls into.

The calculator prices a single order. It does not model whether customers would order more because of the discount, or how orders would shift between tiers.

It assumes a constant variable cost per unit. If your costs fall with volume, rerun the calculation with the cost that applies at each quantity.

Contribution is before fixed costs, rebates paid later, returns and refunds. It is not net profit.