Unit Price Calculator
Unit Price Comparison Calculator
Compare two or three pack sizes by price per kilogram, litre or piece, find the cheapest, and see how much less it costs per unit.
Unit price comparison
$60 for 500 g, $110 for 1 kg, $26 for 200 g
Price per unit
- quantity
- grams ÷ 1,000 = kg; millilitres ÷ 1,000 = litres
- saving
- how much less the cheapest costs per unit, as a % of the dearer price
Worked example
$60 for 500 g, $110 for 1 kg, $26 for 200 g
Product 1: 60 ÷ 0.5 kg = $120 per kg
Product 2: 110 ÷ 1 kg = $110 per kg, the cheapest
Product 3: 26 ÷ 0.2 kg = $130 per kg
Saving against the dearest: (130 − 110) ÷ 130 = 15.4%; against product 1: (120 − 110) ÷ 120 = 8.3%
Reading the unit price, and when the cheapest is not the best buy
Bigger packs are usually, but not always, cheaper per unit. Offers, odd pack sizes and ‘value packs’ can make a smaller pack the better deal, and the only reliable check is the price per kilogram, litre or piece. Enter each pack’s price and size and the calculator does that division for you.
In India the pack should already tell you. Since the Legal Metrology (Packaged Commodities) Amendment Rules, 2022, notified on 28 March 2022, rule 6(11) requires pre-packed goods to show a unit sale price alongside the MRP: per gram for packs under 1 kg and per kilogram above, per millilitre under 1 litre and per litre above, and per piece for things sold by number. It is not needed where the MRP is already the unit price, such as a 1 kg pack. Because small packs show a price per gram, the calculator also gives the cheapest price per gram or millilitre, so you can match it against the label. Note that the MRP is a maximum; the price you actually pay after a discount is what to enter.
Cheapest per unit is not always the best buy. A larger pack costs more money now, may go off before you finish it, and saves nothing if part of it is thrown away. Compare like with like: concentrated and ordinary detergent, or a pack with a different grade, are not the same product at a different size. The calculator refuses to compare grams with millilitres, since that needs the density. For a price after a discount use the discount calculator, and for any other percentage the percentage calculator. This is arithmetic on the figures you enter, not financial advice.
Frequently asked questions
How do I work out the price per kg?
Divide the price by the weight in kilograms. 500 g for 60 is 60 ÷ 0.5 = 120 per kg.
Do packs in India have to show a unit price?
Yes. Under the Legal Metrology (Packaged Commodities) Amendment Rules, 2022, pre-packed goods must show a unit sale price: per gram or per kilogram, per millilitre or per litre, or per piece, depending on the pack size.
Why can’t I compare grams with millilitres?
A millilitre of oil, honey or shampoo does not weigh a gram. Converting needs the product’s density, which the calculator does not know. Compare packs sold in the same kind of unit.
What does the percentage saving mean?
How much less the cheapest costs per unit, as a share of the dearer unit price. At 110 against 130 per kg the cheaper pack costs 15.4% less per kg.
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References
- Legal Metrology (Packaged Commodities) Amendment Rules, 2022 (Ministry of Consumer Affairs, Food and Public Distribution, notified 28 March 2022), rule 6(11): unit sale price on pre-packaged commodities.
- Legal Metrology (Packaged Commodities) Rules, 2011, rule 6 (declarations to be made on every package).
- Legal Metrology Act, 2009.