Unit Price Calculator

Unit Price Calculator — Cut Through Package-Size Tricks

Is the 1.5L bottle at $3.20 better value than the 900ml at $2.10? This free calculator strips away package-size confusion by computing the price per unit — per kg, per litre, per 100g, per item — for every option and ranking them, so the genuinely cheaper choice is obvious in seconds. In-browser, no signup.

Why the Sticker Price Lies

Option A: 900 ml at $2.10 → $2.33 per litre
Option B: 1.5 L at $3.20  → $2.13 per litre  ← cheaper
Option C: 2 L at $4.60    → $2.30 per litre

The middle size wins — not the smallest price,
not the biggest package. Only unit price reveals it.

Retailers know shoppers anchor on the sticker price and assume "bigger = better value." Neither assumption holds reliably — "value" and "family" sizes are sometimes more per unit than the standard size. Unit price is the great equalizer that makes the shelf honest.

It Handles the Unit Conversions

Comparing a 400g bag against a 1.2kg box means nothing until both are per-kg. The calculator normalizes automatically — grams against kilograms, millilitres against litres, singles against multipacks — so you enter the numbers exactly as printed on each package and get directly comparable figures. No mental arithmetic, no conversion errors at the shelf.

Rank the Whole Shelf

Add every size and brand you're weighing; the tool sorts them by unit price and flags the cheapest. A jumble of "5 for $4," "single at $0.85," "1kg at $6.50," and "500g at $3.40" becomes a clean ranked list — the kind of comparison supermarket shelf-labels are supposed to provide but often print in mismatched units or omit entirely.

When the Cheapest Unit Price Isn't the Right Buy

• Perishables — the bulk bargain is a loss if half spoils before use.
• Storage — no room for the giant pack is a real cost.
• Trying something new — buy the small size first; unit price matters once you know you'll use it.

The calculator gives you the objective number; you weigh it against these practical factors. But you can't make a smart trade-off without knowing the real per-unit cost first — and that's exactly what this provides.

Free and Instant

Compare unlimited options locally — no upload, no account. Smarter shopping, one calculation at a time.