Haru ToolsHow to use this tool
A package price is easier to compare when you know what the same quantity costs. Calculate one product at a time, note its unit price, then replace the inputs with the next product. Use grams or kilograms for weight, or millilitres or litres for volume, keeping the same comparison basis for each calculation.
- Enter one package's actual price and total usable quantity, including all units in a multipack.
- Select its unit and a comparison basis. A basis of 100 means price per 100 g for weight or per 100 mL for volume.
- Note the result, then enter the next product using the same basis. Compare weight with weight, or volume with volume.
The calculation, explained
First calculate A: 4.50 currency units for 500 g. Then calculate B: 7.20 for 1 kg.
First result: 0.90 per 100 g. Second result: 0.72 per 100 g.
Package B costs more at checkout but less for the same weight. Its price per 100 g is 20% lower than A's because (0.90 − 0.72) ÷ 0.90 = 0.20.
Normalize quantity before comparing
A kilogram contains 1,000 grams, and a litre contains 1,000 millilitres. These conversions work within a measurement family. Grams and millilitres measure different properties, so converting between them requires the substance's density. The calculator does not assume that every liquid has the density of water.
Use matching prices and package contents
Keep both prices in the same currency and use the same treatment of tax and required charges. For a six-pack containing 250 mL in each container, enter the combined 1,500 mL when the price is for the whole pack. If the comparison depends on drained or usable weight, use that consistently for both products.
The cheaper unit price may not be the better purchase
A larger pack can have a lower unit price but cause waste if you cannot finish it. Concentration, ingredients, quality, portion size, storage, and expiry dates also matter. For products that are diluted before use, compare equivalent prepared quantities only when you know the directions and yield.
Questions that come up
Can I compare grams with kilograms?
Yes. Calculate each product in turn using the same basis and compare the results. Grams and kilograms normalize to the same weight unit; millilitres and litres likewise normalize as volume.
Does this convert currencies?
No. Enter both prices in the same currency. The output remains in that currency per the selected quantity basis.
What does changing the basis do?
It changes the displayed scale, not which compatible product has the lower unit price. A price of 0.72 per 100 g is the same rate as 7.20 per 1,000 g.
Reviewed: September 21, 2026 · Haru Tools editorial