A
First option
Product A
Normalised unit price—Enter valid values
Everyday shopping calculator
All calculatorsUnit Price Calculator
Compare two packages by cost per kilogram, litre, ounce, pound, item, serving, sheet, tablet, or other common unit.
Compare two products
Which package offers better value?
Enter the price, quantity, and measurement unit for both products. The calculator converts compatible units before comparing their true unit cost.
B
Second option
Product B
Normalised unit price—Enter valid values
Unit-price formula
How is unit price calculated?
Divide the total package price by the number of units inside the package. Both products must be converted to the same comparison unit before deciding which one is cheaper.
FormulaUnit price = total price ÷ quantity
A package costing $12 with 6 items has a unit price of $2 per item.
Comparison process
Calculate unit price step by step
Use the same process whether you are comparing groceries, cleaning products, toiletries, medicine packs, or bulk goods.
Record the package price
Use the final price you expect to pay after any instant discount that applies to both the product and the purchase.
Record the package quantity
Find the net weight, liquid volume, item count, serving count, sheet count, or another useful quantity.
Convert compatible units
Convert grams to kilograms, millilitres to litres, or ounces to pounds before comparing differently labelled packs.
Choose the lower unit cost
The product with the lower cost for the same measurement unit offers the better mathematical value.
Worked example
Compare two packages of the same product
Suppose Product A costs $12 for 6 items and Product B costs $18 for 10 items.
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Result
Product B costs $0.20 less per item. Its unit price is 10% lower than Product A's unit price.
Package size
Is the larger package always cheaper?
No. Larger packages often have a lower unit price, but the label, sale price, brand, package design, or promotional offer can make a smaller pack cheaper per unit.
Small package500 g$4.50$9.00 per kg
Large package1 kg$8.20$8.20 per kg
Better valueLarge packageSave $0.80 per kg
Compatible measurements
Compare products using the same type of unit
Weight can be compared with weight, volume with volume, and item counts with compatible item counts. A weight-based pack cannot be compared directly with a volume-based pack without additional product-density information.
Useful for flour, rice, meat, vegetables, snacks, and other products sold by net weight.
Useful for milk, juice, detergent, shampoo, oil, and other liquid products.
Useful for eggs, tissues, capsules, servings, rolls, and multipack products.
Sales and coupons
Use the price you will actually pay
Unit-price labels may be based on the regular shelf price. When a sale, coupon, loyalty offer, or multi-buy promotion changes the final price, calculate unit cost using the amount you will actually pay.
Shopping decisions
The lowest unit price is not always the best purchase
Unit price measures cost efficiency, but it does not measure quality, freshness, convenience, product preference, or waste.
A bulk package may not be practical when storage space is limited.
A lower unit price does not save money when part of the product expires before use.
Two products can have different ingredients, durability, concentration, or performance.
A larger package may have a lower unit price but require a higher immediate payment.
Avoid errors
Common unit-price mistakes
Convert both products to the same unit before comparing their costs.
A lower package price does not necessarily mean a lower price per unit.
Apply valid coupons and discounts before calculating the final unit price.
Buying more than you can use may erase the saving from a lower unit price.
Related tools
Related calculators
Unit Price guides
Learn more about comparing unit prices
Use these supporting guides for package comparisons, grocery shopping, weights, volumes, item counts, and bulk purchases.
Supporting guideHow to Calculate Unit Price
Use the basic unit-price formula with clear grocery and household examples.
Read guide →Supporting guideHow to Compare Unit PricesCompare two packages fairly even when their sizes and prices are different.
Read guide →Supporting guideUnit Price vs Total PriceUnderstand why the cheapest package price is not always the best value.
Read guide →Supporting guideHow to Find Price per OunceCalculate and compare package prices using ounces as the common unit.
Read guide →Supporting guideHow to Find Price per PoundConvert package quantities and calculate the cost of one pound.
Read guide →Supporting guideHow to Find Price per GramFind the cost of each gram and compare metric package sizes.
Read guide →Supporting guideHow to Find Price per ItemCompare multipacks, boxes, tablets, sheets, servings, and individual items.
Read guide →Supporting guideHow to Compare Different Package SizesNormalise units before comparing products sold in different package formats.
Read guide →Supporting guideIs the Larger Package Always Cheaper?Check whether a family-size or bulk package truly offers a lower unit cost.
Read guide →Supporting guideUnit Price Calculator for Grocery ShoppingUse unit pricing to compare food, cleaning products, toiletries, and household goods.
Read guide →Questions answered
Unit Price Calculator FAQs
What is unit price?
Unit price is the cost of one standard unit, such as one item, one kilogram, one litre, one ounce, or one serving.
How do I calculate unit price?
Divide the total package price by the package quantity. Convert both products to the same measurement unit before comparing them.
Which product is the better value?
The product with the lower cost for the same unit is the better mathematical value.
Can I compare grams with kilograms?
Yes. Convert both quantities to grams or kilograms before comparing their unit prices.
Can I compare millilitres with litres?
Yes. One litre equals 1,000 millilitres, so both quantities can be converted to the same volume unit.
Is the bigger package always cheaper per unit?
No. Promotions, brands, packaging, and pricing strategies can make a smaller package cheaper per unit.
Should I include a coupon in the calculation?
Yes, when the coupon applies to the purchase. Use the final amount you will actually pay.
Can I compare weight with volume?
Not directly. Weight and volume require product-density information before they can be converted reliably.
What if both unit prices are equal?
Neither product has a unit-price advantage. Choose based on quality, package size, storage, preference, and convenience.
Does the lowest unit price always save money?
Not when excess product is wasted, expires, or requires more cash than you want to spend immediately.
Compare before you buy
Compare productsFind the better unit price in seconds
Enter both package prices, quantities, and measurement units to see which product offers the lower normalised cost.