Compare unit prices between pack sizes

Normalize differently sized packs to one price per 100 comparable units and rank the cheapest against the most expensive.

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ToolUnit Price Comparator
Input
Output
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Preview

How it works

Each selling price is divided by its quantity and multiplied by 100, then the normalized rows are ranked from lowest to highest. Percentage saving is the gap between the highest and lowest normalized prices divided by the highest price.

Formula
price per 100 = selling price ÷ quantity × 100
  • At least two packs are required, and all quantities must already use the same unit.
  • The per-100 display follows common shelf-label readability; it is not a substitute for statutory per-kilogram or per-litre labelling.

Worked example

Two sizes of the same bottle
Input
											3.50 750 ml bottle,5.60 1000 ml bottle
Output
												Packs compared: 2
Best pack: 750 ml bottle
Best price per100: 0.47
Worst pack: 1000 ml bottle
Worst price per100: 0.56
Savings percent: 16.67

When to use this

Grocery comparisons normalize cereal by grams, cleaning refills by millilitres, and office multi-packs by comparable sheets, batteries, or pens.

Edge cases

  • A 500 g pack and a 2 kg pack cannot be entered as 500 and 2; convert both to grams or both to kilograms before comparing.
  • Six 330 ml cans contain 1,980 ml, so comparing that multipack with a bottle by volume requires the combined contents rather than quantity 6.
  • A cheaper normalized result ignores spoilage, delivery, deposits, loyalty conditions, and product quality because only selling price and comparable quantity enter the arithmetic.

References