🧮 Calculators & Daily Life

Unit Price Comparison

Enter price and quantity to work out the price per gram, per ml, or per item, and compare which product is cheaper. The cheapest is highlighted automatically. Great for groceries and bulk buys. Everything stays in your browser.

Examples (click to try)

How to Use the Unit Price Comparison

New here? Tap one of the Examples (click to try) buttons above — two products fill in with a price and quantity, and the result appears instantly. Once you're comfortable, type in your own numbers. Each time you enter or change a price or quantity, every product's unit price recalculates live and the cheapest one is highlighted in green — no button to press.

  1. Enter a Unit label (optional — e.g. g, ml, item; it's just for display and can be left blank).
  2. Enter each product's Price (the tax-included price is best).
  3. Enter each product's Quantity. Use the same unit for every product you compare (enter 1 kg as 1000 g).
  4. To compare three or more, use “＋ Add product” (up to 4).

Worked Example (price and quantity → unit price)

Compare A: ¥298 / 500 g with B: ¥450 / 1 kg (= 1000 g). A is 298 ÷ 500 = 0.596 ¥/g, and B is 450 ÷ 1000 = 0.45 ¥/g. Per gram, B is cheaper — about 24% cheaper than A (0.596 ¥/g). Looking only at the shelf price (¥298 vs ¥450), A seems cheaper, but converting to price per unit shows B is the better deal. Lining up the units and comparing the unit price is the trick to not overpaying on bulk buys and sales.

Tips for Matching Units

  • Weight: convert kg to g (0.5 kg → 500 g, 1.2 kg → 1200 g), then compare everything in grams.
  • Volume: convert L to ml (1 L → 1000 ml), then compare in ml.
  • Count: for “12-pack” or “200 sheets”, put the count itself in Quantity and compare per item (per sheet).

Compare Faster

Tap an example chip to fill both products at once and see the result immediately. Within the fields, press Tab to jump to the next box, so you can type price → quantity → next product in a rhythm. The cheapest product is shown with a green highlight and a one-line “X% cheaper” note, so a single glance tells you which to buy. Use “Copy Result” to paste the full list of unit prices and share it.

Frequently Asked Questions

Are the prices and quantities I enter sent to a server?
No. All unit-price calculations happen entirely in your browser (on your device). The prices and quantities you enter are never transmitted to or stored on any external server. You can use this tool with complete confidence.
Do the quantity units need to match?
Yes. For products you want to compare, enter the quantity in the same unit (all in grams, or all in ml, or all in items). For example, enter a 1 kg product as 1000 g so the per-gram prices line up correctly. The unit label is just an optional display field.
What if the unit prices are very close?
The tool highlights the cheapest product in green and shows how many percent cheaper it is than the next best option. If the difference is tiny (within a few percent), also consider whether you can use up the larger quantity, the expiry date, and storage space before deciding.