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Unit Price Calculator

Compare prices per unit, per ounce, pound, liter or item, across up to four pack sizes or quotes and see which is the better buy. Mix units of the same kind: the calculator converts pounds to ounces and gallons to fluid ounces for you.

Your numbers

Weight, volume or items: every item needs a unit of the same kind.

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Best buy

Item A
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Item B
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Fluid ounces are US fluid ounces. Weight and volume do not convert into each other: 16 fl oz is not a pound.

The calculation runs in your browser and ParrotNotes does not store your numbers. They sit in the page address so you can bookmark or share the result.

How the unit price is calculated

Unit price = price ÷ quantity. A 24 oz jar of peanut butter at $5.99 is $5.99 ÷ 24 = $0.2496 per ounce. A 12 oz jar at $3.49 is $0.2908 per ounce. The big jar is the better buy, and the small one costs 16.5% more per ounce: ($0.2908 − $0.2496) ÷ $0.2496.

When the packs use different units, convert them to one unit first. The calculator does it for you: enter one pack in pounds and another in ounces, choose what to compare by, and every price is shown per that unit.

Worked examples

Coffee: 12 oz for $8.99 against 2 lb for $21.99. 2 lb is 32 oz, so the bag is $21.99 ÷ 32 = $0.687 per ounce against $0.749 for the small one: the 2 lb bag is 8.3% cheaper per ounce.

Milk: a half gallon for $2.79 against a gallon for $4.49. A half gallon is 2 quarts, so that is $1.395 per quart against $1.1225 per quart for the gallon. Paper towels: 6 rolls for $8.99 and 12 rolls for $19.49 are $1.50 and $1.62 per roll, so here the smaller pack wins.

Weight, volume and count do not mix

An ounce (oz) is a weight and a fluid ounce (fl oz) is a volume. 16 fl oz of water weighs about a pound, but 16 fl oz of honey or of cereal does not, so the calculator only compares weight with weight, volume with volume and items with items. If one pack is sold by weight and the other by volume, look for the other number on the label; many packs print both.

Fluid ounces here are US fluid ounces: 128 to the gallon, 29.57 ml each. Pounds and ounces are the avoirdupois units on every US grocery label (1 lb = 16 oz = 453.59 g).

Comparing supplier quotes and case prices

The same sum settles a buying decision at work. One distributor quotes $186 for a case of 24, another $412 for a pallet layer of 60, a third $7.40 each: compare per item and the calculator shows the cheapest and how much more the others cost. For bulk materials compare per pound, per gallon or per 100 items.

The unit price is not the whole cost. Minimum order quantities, freight, lead time and payment terms can turn the cheapest unit price into the dearest delivered price, and those terms are usually settled on the phone. Ask each supplier the same questions and write the answers next to the price.

Unit prices on shelf tags

Many US stores print a unit price on the shelf tag, but it is required by law only in some states and voluntary in the rest, and the unit can change from one product to the next: one brand per ounce, the next per count. NIST's unit pricing guide asks stores to use one unit within a category; when they do not, this calculator puts both on the same unit.

Got a percent off on top? Work out the sale price with the discount calculator.

For reps comparing quotes: What an RFQ is, Building materials sales, What a wholesale sales rep does.

Comparing supplier quotes? The terms are on the call.

The unit price is one line of the quote. Minimums, freight, lead times and the discount the supplier offered are said on the call. ParrotNotes records the conversation (with permission), writes the summary and pulls out the terms and next steps.

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Unit price calculator FAQ