# Unit Price Calculator — Find the Best Grocery Value

> Compare grocery options by real cost per 100 g, per litre, or per item — across pack sizes and discounts — to spot the best value in the aisle. Multi-currency, free.

- **Category:** Lifestyle & Everyday
- **Interactive calculator:** https://youcalc.com/en/lifestyle-everyday/grocery-unit-price/
- **Price:** Free, no sign-up required

## Overview

The "value" pack is not always the better buy. Shelf prices hide the real cost because every option comes in a different size, and a promotion on the small pack can quietly beat the big one. This calculator puts each option on the same footing — cost per 100 g, per litre, or per item — so the best value is obvious. Punch in the price and size of each option (add a discount if one is on offer) right there in the aisle and let the cheapest unit price decide.

## How to read your result

Pick what you are comparing at the top — weight, volume, or count — then add a row for each option with its price, pack size, and unit. The headline is the cheapest option's unit price, with the eyebrow "Best value", and the winning row is marked with a chip. The stats name the cheapest item, show how much cheaper it is than the priciest option as a percentage, and count how many options you compared. Every row shows its own unit price, so even the options that did not win are easy to read off.

## Method

Each option is converted to a common base unit before comparing. Weight units convert to grams (g ×1, kg ×1000, oz ×28.349523125, lb ×453.59237); volume units convert to millilitres (ml ×1, L ×1000, fl oz ×29.5735295625); count uses each (×1). The price is first reduced by any discount: effective price = price × (1 − discount% ÷ 100). The cost per base unit is the effective price ÷ size-in-base, which is then scaled to a friendly figure: per 100 g for weight, per litre for volume, per item for count. The option with the lowest scaled unit price is the best value; "cheaper than priciest" is (most expensive − cheapest) ÷ most expensive, as a percentage. Item names stay in your browser for the session and are never stored or put in a shared link — the link records each option's price, size, unit, and discount so the comparison reproduces exactly.

## Example

- **Setup:** Comparing by weight: a 500 g jar of coffee at $5.00, and a 1 kg jar at $8.00 with no discount.
- **Result:** The 500 g jar works out to $1.00 per 100 g, while the 1 kg jar is $0.80 per 100 g. The big jar wins — it is 20% cheaper per unit, even though its sticker price is higher. If the 1 kg jar instead had 20% off ($6.40), it would drop to $0.64 per 100 g and win by an even wider margin.

## Frequently asked questions

### Why is the bigger pack sometimes not the better deal?

Stores often price larger packs to feel like a saving, but the cost per 100 g, per litre, or per item can be the same or even higher than a smaller pack — particularly when the smaller size is on promotion. Comparing the unit price removes the pack-size illusion so you can see the real cost and buy the genuinely cheaper option.

### How do I handle an item that is on offer?

Use the discount field. Enter the percentage off and the calculator lowers that option's price before working out its unit price. For example, a 1 kg pack at $10 with 20% off is compared at its effective $8 — which lets you check whether the discounted big pack actually beats a smaller pack at full price, rather than just assuming it does.

### Can I compare weight against volume, or items against grams?

No, and that is deliberate. A unit price only means something when every option shares the same base unit, so each comparison uses one measure type — weight, volume, or count. Switch the measure at the top and every row adopts that family's units. Comparing a 500 g jar to a 500 ml bottle would not give a meaningful "better value" answer.

### Is the unit price a guaranteed price?

No. It is arithmetic on the price and size you type in, meant to help you compare options quickly on the shelf. Always check the store's own unit-price label too, since drained weights, pack contents, and promotions vary by store and change over time.

## Related calculators

- [Discount Calculator](https://youcalc.com/en/lifestyle-everyday/discount/)
- [Subscription Audit Calculator](https://youcalc.com/en/lifestyle-everyday/subscription-audit/)

## Sources

- https://www.consumerfinance.gov/consumer-tools/

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Interactive version: https://youcalc.com/en/lifestyle-everyday/grocery-unit-price/ · From YouCalc — https://youcalc.com