Unit Price Comparison Calculator
Compare the unit price of two products to find the better deal.
Enter the price and size of each item to see which offers more value.
Unit price comparison calculates the cost per standardized unit (per ounce, per gram, per liter, per sheet, per count) to determine which of two or more products is the genuine best value — regardless of package size, brand, or promotional packaging.
Core formula: Unit Price = Total Price ÷ Total Quantity Savings % = (Higher Unit Price − Lower Unit Price) ÷ Higher Unit Price × 100
What each variable means:
- Total Price — the shelf price or sale price of the item as packaged.
- Total Quantity — the amount of product inside: in ounces, grams, liters, sheets, count, etc. Always compare the same unit type.
- Unit Price — the cost per single unit of measurement. Lower unit price = better value per unit (though quality differences also matter).
- Standardized comparison — the only fair comparison. A 32 oz bottle at $4.99 vs. a 48 oz bottle at $6.99 cannot be compared by total price alone.
Common unit price comparisons:
| Product Category | Compare By | Notes |
|---|---|---|
| Beverages | Per fl oz or per liter | Watch for added sugar/water |
| Dry food (rice, pasta, cereal) | Per ounce or per gram | |
| Paper products (toilet paper) | Per sheet | Compare ply count too |
| Cleaning products | Per fl oz | Concentration matters |
| Medications | Per tablet/capsule or per mg | Check dosage strength |
| Produce | Per pound or per kg | |
| Batteries | Per battery | Check mAh for energy capacity |
Worked example 1 — Peanut butter: Brand A: 18 oz jar at $3.99 Brand B: 28 oz jar at $5.49
Unit price A = $3.99 ÷ 18 = $0.222/oz Unit price B = $5.49 ÷ 28 = $0.196/oz
Brand B saves: (0.222 − 0.196) ÷ 0.222 × 100 = 11.7% cheaper per ounce
Worked example 2 — Toilet paper: Pack A: 12 double rolls (200 sheets each) at $8.99 Pack B: 6 mega rolls (500 sheets each) at $11.49
Total sheets A: 12 × 200 = 2,400 sheets → $8.99 ÷ 2,400 = $0.00375/sheet Total sheets B: 6 × 500 = 3,000 sheets → $11.49 ÷ 3,000 = $0.00383/sheet
Pack A is cheaper per sheet despite appearing more expensive. The mega roll marketing is misleading here.
Smart shopping rule: Always divide price by quantity. Never trust “value size” or “bulk” labeling without checking the math.