What unit should I use?

Use the unit that matches the product (kg, L, item, etc.). The result is total price divided by quantity; you can compare any two options as long as you use the same unit for each.

How is rounding handled?

Results are shown with a sensible number of decimal places. Exact math is used internally; rounding is only for display so the numbers stay readable.

What if the two products use different units?

Convert to a common unit first (e.g. both to kg or both to per 100 g). Then calculate unit price for each in that unit so you compare like for like.

Do taxes or coupons change the unit price?

Unit price is based on what you enter. If you pay after tax or after a coupon, use that final price and the same quantity to get the true unit cost you pay.

Why use “per 100 g” or “per 100 mL”?

Many labels use per 100 g or per 100 mL so you can compare different pack sizes at a glance. This tool can give you the same style of number for any unit you choose.

Why do unit prices differ between stores?

Stores set their own prices and may run different promotions. Always recalculate with the price and size you see where you shop.

Does unit price include weight of packaging?

No. Unit price is based on the quantity you enter (e.g. net weight or volume on the label). Packaging weight is not included in the calculation.

Can I compare different package sizes of the same product?

Yes. Enter price and quantity for each size; the unit price tells you which size is better value per unit.

What if the quantity is in “items” (e.g. 12 rolls)?

Use the number of items as the quantity and a unit like “items” or “count”. The result is price per item.

Are results suitable for business or bulk buying?

The formula is the same; use your actual price and quantity. For very large orders, confirm with the supplier and consider delivery and minimum orders.

Why might my result differ from the store’s “per 100 g” label?

Small differences can come from rounding or from the store using a slightly different quantity (e.g. net vs drained weight). Use your own numbers for the purchase you are making.

Is the calculator free and private?

Yes. It runs in your browser; we don’t store your inputs or results.

Unit Price Calculator

Use this calculator to find the price per unit (per kg, per litre, per item, etc.) so you can compare different package sizes and brands fairly. Unit price strips away packaging and size so you see which option gives you the best value. Ideal for groceries, household products, and bulk vs single-item choices.

Total Price ($)QuantityUnit label

Price per unit

Informational only; verify critical results independently.

How to use

Enter the total price you pay (or see on the shelf) and the quantity (amount + unit, e.g. 1.5 kg, 750 mL, 12 items).
Choose or type the unit that matches the quantity (kg, g, L, mL, count, etc.).
Read the result: price per unit in the same unit (e.g. cost per kg, per litre, per item).
To compare two products, calculate the unit price for each and compare those numbers.
For groceries, using “per 100 g” or “per 100 mL” makes it easy to compare different pack sizes.
If one product is in kg and another in g, convert to the same unit (e.g. 500 g = 0.5 kg) or use per 100 g for both.
Consider rounding: small differences in unit price may not matter for a single purchase; they add up over many.
Watch for “per 100 g” or “per 100 mL” labels on shelves; this tool gives you the same style of comparison for any unit.
Use the same unit for quantity and result (e.g. price per L when quantity is in L) for a direct comparison.
Common pitfalls: mixing units (e.g. price for 500 g vs quantity in kg), or forgetting to include the full quantity (e.g. “per roll” when the pack has 6 rolls).

Examples

$8.99 for 750 mL olive oil — unit price about $11.99/L.
$10.49 for 1 L same brand — unit price $10.49/L; the 1 L is better value.
$12 for 18 eggs vs $9 for 12 eggs — per-egg cost shows which carton is cheaper per egg.
$5.49 for 400 g pasta vs $7.99 for 1 kg — compare per kg or per 100 g to see the bulk option.
£3.50 for 6 rolls of toilet paper vs £4.20 for 9 rolls — unit price per roll for a fair comparison.
2 for $6 (each 350 mL) vs one 1 L at $7 — work out per litre for both to decide.
Bulk bin: $4.50 per kg vs packaged 500 g at $2.80 — per kg or per 100 g makes them comparable.
Detergent: 2 L at $14 vs 1.5 L at $10 — unit price per litre shows the better deal.
Cereal: 450 g at $5 vs 750 g at $7.50 — per 100 g or per kg for a clear comparison.
Coffee: 200 g at $8 vs 1 kg at $32 — per 100 g or per kg to compare.

FAQ

What unit should I use?: Use the unit that matches the product (kg, L, item, etc.). The result is total price divided by quantity; you can compare any two options as long as you use the same unit for each.
How is rounding handled?: Results are shown with a sensible number of decimal places. Exact math is used internally; rounding is only for display so the numbers stay readable.
What if the two products use different units?: Convert to a common unit first (e.g. both to kg or both to per 100 g). Then calculate unit price for each in that unit so you compare like for like.
Do taxes or coupons change the unit price?: Unit price is based on what you enter. If you pay after tax or after a coupon, use that final price and the same quantity to get the true unit cost you pay.
Why use “per 100 g” or “per 100 mL”?: Many labels use per 100 g or per 100 mL so you can compare different pack sizes at a glance. This tool can give you the same style of number for any unit you choose.
Why do unit prices differ between stores?: Stores set their own prices and may run different promotions. Always recalculate with the price and size you see where you shop.
Does unit price include weight of packaging?: No. Unit price is based on the quantity you enter (e.g. net weight or volume on the label). Packaging weight is not included in the calculation.
Can I compare different package sizes of the same product?: Yes. Enter price and quantity for each size; the unit price tells you which size is better value per unit.
What if the quantity is in “items” (e.g. 12 rolls)?: Use the number of items as the quantity and a unit like “items” or “count”. The result is price per item.
Are results suitable for business or bulk buying?: The formula is the same; use your actual price and quantity. For very large orders, confirm with the supplier and consider delivery and minimum orders.
Why might my result differ from the store’s “per 100 g” label?: Small differences can come from rounding or from the store using a slightly different quantity (e.g. net vs drained weight). Use your own numbers for the purchase you are making.
Is the calculator free and private?: Yes. It runs in your browser; we don’t store your inputs or results.

Formula / Method

Unit price = total price ÷ quantity. For example, if you pay $6 for 1.5 kg, unit price = 6 ÷ 1.5 = $4 per kg. Use the same units for quantity and result (e.g. price per L when quantity is in litres).

Assumptions & Limitations

Results are for comparison only and depend on the price and quantity you enter. They do not account for quality, freshness, or your own preferences. Packaging and store-specific offers are not included.

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Last updated: 2025-09-15

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