CalcLibrary

Unit Price Comparison

Compare two to five differently-sized packages of the same product to see which is cheapest per unit. Enter the size and price of each, choose the unit you are pricing by (oz, g, ml, sheets, count, anything you like), and the calculator divides price by size for each row, highlights the lowest per-unit price, and shows how much cheaper it is than the most expensive option.

Currency
Comparison setup
Package A
$
Package B
$
Examples

A 250 g jar at 3.99 vs a 500 g jar at 6.49 — which is cheaper per gram?

Orchard Lane 500g is cheapest
$0.0130 per g
Savings vs most expensive
19%

Orchard Lane 500g is 19% cheaper per unit than the most expensive option here.

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Examples

How It Works

Formula

pi=priceisizeip_i = \dfrac{\text{price}_i}{\text{size}_i}

savings%=(1−min⁡ipimax⁡ipi)×100\text{savings\%} = \left(1 - \dfrac{\min_i p_i}{\max_i p_i}\right) \times 100

Variables

pip_i

Per-unit price of package i

pricei\text{price}_i

What package i costs

sizei\text{size}_i

How many units package i contains

Choose two to five packages, then enter the size and price for each package you want to compare. Type the unit you are pricing by — oz, g, ml, sheets, anything — into the Unit field. The calculator divides price by size for each active row, highlights the lowest per-unit price as the hero, and shows how much cheaper it is than the most expensive option as a percentage.

Frequently Asked Questions

01How is the per-unit price calculated?
Price ÷ size, separately for each package. A 500 g jar at 6.49 works out to 6.49 / 500 = 0.013 per gram. Choose how many packages you want to compare, then the calculator shows every active row side by side in your selected currency.
02Is the cheapest per unit always the right buy?
Not always. A bigger pack is only the better deal if you actually use it before it spoils, and if you have room to store it. A smaller pack can be the smarter choice when waste is a real risk — the calculator answers "cheapest per unit", which is one signal of value, not the whole picture.
03Can I compare a package measured in ounces against one in grams?
No — this calculator does not convert between units. Use the same unit label across all rows, or convert the sizes yourself first with a length, weight, or volume converter. Comparing 12 oz to 500 g without converting will give you a meaningless ratio.
04What unit should I type in the Unit field?
Whatever the package is sold by — oz, g, ml, sheets, count, tea bags, eggs, square feet, anything that fits. The label is cosmetic; it appears next to each price so you can read the result as e.g. "0.50 / oz" without ambiguity. The math is the same no matter what you type.
05How is this different from the discount, tip, or split-bill calculators?
Those three each work on a single bill: the discount calculator takes a percent off one price, the tip calculator adds a tip to one bill, and the split-bill calculator divides one bill among several people. Unit price comparison is the only one that compares per-unit cost across several package sizes — apples to apples on a per-unit basis.

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