What Is Unit Price?
Unit price is the cost per single unit of measurement (per ounce, per liter, per item, etc.). It is the most reliable way to compare products of different sizes, brands, or packaging. Most grocery stores display unit prices on shelf labels, but knowing how to calculate it yourself ensures you always get the best value for your money.
The Unit Price Formula
Step-by-Step Example
Compare two bottles of olive oil:
- Brand A: 16 oz for $6.49
- Brand B: 25 oz for $8.99
- Brand A unit price: $6.49 ÷ 16 = $0.406 per oz
- Brand B unit price: $8.99 ÷ 25 = $0.360 per oz
- Brand B is cheaper per ounce — saving about 4.6 cents per ounce.
Common Unit Price Comparisons
| Product | Option A | Option B | Better Deal |
|---|---|---|---|
| Cereal | 12 oz / $3.49 ($0.291/oz) | 18 oz / $4.79 ($0.266/oz) | Option B |
| Laundry detergent | 50 oz / $7.99 ($0.160/oz) | 100 oz / $13.99 ($0.140/oz) | Option B |
| Paper towels | 6 rolls / $5.99 ($1.00/roll) | 12 rolls / $10.49 ($0.87/roll) | Option B |
| Yogurt | 6 oz cup / $0.89 ($0.148/oz) | 32 oz tub / $3.99 ($0.125/oz) | Option B |
When Bulk Buying Is NOT Worth It
A lower unit price does not always mean a better deal. Consider these factors before buying in bulk.
- Perishable goods: If you cannot consume it before it expires, you waste money no matter the unit price.
- Storage limitations: No room to store 48 rolls of paper towels? The savings may not justify the inconvenience.
- Cash flow: Spending $40 on bulk pasta when you only need $5 worth ties up money you might need elsewhere.
- Quality differences: A cheaper unit price does not mean equal quality. A $0.10/oz mediocre sauce is not better than a $0.15/oz excellent one.
- Sale prices on smaller sizes: Sometimes a smaller size on sale beats the everyday bulk price.
Unit Price in Different Measurement Systems
| Product Type | Common Unit (US) | Common Unit (Metric) |
|---|---|---|
| Liquids | Per fluid ounce | Per liter or 100 mL |
| Solid foods | Per ounce or per pound | Per gram or per kilogram |
| Packaged items | Per count (per sheet, per pod) | Per count |
| Produce | Per pound | Per kilogram |
Quick Percentage Savings Calculation
Once you know the unit prices, calculate how much you save by choosing the cheaper option:
Example: Brand A is $0.406/oz and Brand B is $0.360/oz:
Savings = (($0.406 - $0.360) ÷ $0.406) × 100 = 11.3% savings by choosing Brand B.
Smart Shopping Tips
- Always compare unit prices, not total prices — the bigger package is not always cheaper per unit.
- Check store brands: They often have significantly lower unit prices than name brands for equivalent quality.
- Use a calculator app: Quickly compare unit prices while shopping.
- Look at the shelf tag: Most stores show the unit price in small print on the price label.
- Consider price per use: For non-consumables, think about cost per use rather than cost per unit.
Try Our Free Calculator
Put your knowledge into practice with our easy-to-use percentage calculator.
Use Calculator