Enter the price and size of two or more packs. Tabel converts them to the same unit, such as price per kg or per litre, and shows which costs less.
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Which pack is cheaper?
Enter two or more packs, in any units. Tabel converts them to the same measure and shows the cheapest.
Up to six packs. Nothing you type leaves this page.
Results appear here as you type.
How unit price is calculated
Comparable unit price = pack price ÷ quantity after conversion to the base unit. Count becomes each, mass becomes kg, volume becomes L, length becomes m and area becomes m². A case of 6 bottles × 500 ml contains 3,000 ml: enter 3000 ml, or 3 L.
A worked example
A 3 L oil pack priced at 42 USD costs 14 USD/L. A 1,000 ml bottle at 14.70 USD costs 14.70 USD/L. The smaller pack has the lower ticket price and the higher unit price.
US liquid and imperial gallons are separate choices. An ounce without “fluid” is mass. We do not infer quantities for boxes, cases or pallets, or convert mass to volume without density. Price excludes freight, tax and order minimums.
Keep the whole comparison in view
Have several supplier spreadsheets? Open the comparison desk to map columns, review identity and preserve source evidence.
How to work out the price per kg or per litre
Divide the price by the amount in the pack, after putting that amount in the unit you want to compare. For a price per kilogram, change grams to kilograms first: 400 g is 0.4 kg. A 400 g pack at $7.96 costs 7.96 ÷ 0.4 = $19.90 per kg. For a price per 100 g, divide by 4 instead, because 400 g is four lots of 100 g: $1.99 per 100 g.
The same rule works for everything. Price ÷ millilitres × 1,000 gives the price per litre. Price ÷ number of items gives the price per item. The calculator above does the conversions for you, including ounces, pounds, fluid ounces and gallons, so two packs labelled in different units still end up side by side.
Worked examples
Each table below was produced by the calculator on this page. Prices are illustrative; use the prices on your own shelf or receipt.
Coffee beans: 12 oz bag or 2 lb bag?
Pack
Price
Price per lb
Versus cheapest
12 oz bag
$8.99
$11.99 / lb
+19.9%
2 lb bag
$19.99
$10.00 / lb
Cheapest
Olive oil: three bottle sizes
Pack
Price
Price per L
Versus cheapest
500 ml bottle
$6.49
$12.98 / L
+21.7%
1 L bottle
$11.99
$11.99 / L
+12.4%
3 L tin
$32.00
$10.67 / L
Cheapest
Sparkling water: six cans or one big bottle?
Pack
Price
Price per L
Versus cheapest
6 × 330 ml cans (1,980 ml)
$3.99
$2.02 / L
+125.2%
2 L bottle
$1.79
$0.895 / L
Cheapest
Eggs: a dozen or eighteen?
Pack
Price
Price per egg
Versus cheapest
12 eggs
$4.29
$0.358 / egg
+7.4%
18 eggs
$5.99
$0.333 / egg
Cheapest
Is the bigger pack always cheaper?
Usually, but not always. A promoted small pack is often cheaper per kilogram than the large pack next to it, and some “family size” packs cost more per unit than two regular ones. Compare the unit price, not the ticket price. Then ask whether you will use the larger pack before it expires: a lower unit price saves nothing if half of it is thrown away.
Multipacks and “3 for 2” offers
Enter what you would actually pay and everything you would actually get. Six 330 ml cans hold 1,980 ml in total. For a “3 for 2” offer on $2.50 packs of 500 g, enter $5.00 for 1,500 g: that is $3.33 per kg, against $5.00 per kg for a single pack.
Ounces are not fluid ounces
An ounce (oz) is a weight; a fluid ounce (fl oz) is a volume. A 16 fl oz bottle of oil does not hold 16 oz by weight, so the two cannot be compared directly. Compare fluid ounces with fluid ounces, or put both packs in millilitres. US and imperial fluid ounces and gallons are also different sizes; the calculator lists them separately.
Unit prices on shelf labels
Many shelf labels already show a unit price, but similar products are not always labelled in the same unit: one says per 100 g, the next per kg, or per sheet against per roll. Enter both packs here to put them on one unit. In the UK, the Price Marking Order 2004 requires most retailers to show a unit price, and in the EU Directive 98/6/EC does the same. In the US, unit pricing rules are set by each state; NIST Handbook 130 contains the model Uniform Unit Pricing Regulation.
Questions people ask
How do I calculate the price per kg when the pack isn’t 1 kg?
Divide the price by the weight in kilograms. 250 g is 0.25 kg, 500 g is 0.5 kg and 1.5 kg stays 1.5. A 250 g pack at $3.20 costs 3.20 ÷ 0.25 = $12.80 per kg.
How do I compare price per ounce with price per pound?
There are 16 ounces in a pound, so multiply a price per ounce by 16 to get the price per pound. Or enter both packs above and choose “lb” or “oz” under “Show the price per”.
How do I find the price per item?
Divide the pack price by the number of items: 18 eggs at $5.99 cost $0.3328 each. Choose “item” as the unit.
Does the calculator store what I type?
No. The arithmetic runs in your browser. Prices and quantities are not sent anywhere or saved.
Buying for a business?
For quotes with freight, duty, tax and whole-pack rounding, use the landed cost calculator. To compare full supplier price lists in Excel or CSV, open the comparison desk.
