OptiDrop

Unit Price Comparator Online — Find the Best Deal Free

Compare price per unit across up to 5 products to find the best value. Supports kg, g, lb, oz, L, ml, and gal. The cheapest option is highlighted. 100% free, no sign-up required.

Free Unit Price Comparator Online — Find the Best Deal

OptiDrop's Unit Price Comparator is a free online tool that helps you compare the price per unit across multiple products. Enter up to 5 products with their prices, quantities, and units, and the tool calculates the unit price for each and highlights the cheapest option. Perfect for smart grocery shopping and finding the best value.

How Does the Unit Price Comparator Work?

Enter each product's name, price, quantity, and unit of measurement. The tool converts all quantities to a common base unit (grams for weight, milliliters for volume), then divides the price by the converted quantity to get the price per base unit. The product with the lowest unit price is highlighted as the best deal.

Smart Shopping Tips

Always compare unit prices, not just shelf prices. A larger package is not always cheaper per unit. Stores sometimes price smaller packages lower per unit to move inventory. Use this tool every time you shop to make sure you are getting the best value. All calculations happen in your browser with no data uploaded anywhere.

Frequently Asked Questions

Enter the product name, price, quantity, and unit (kg, g, lb, oz, L, ml, gal) for up to 5 products. The tool converts all quantities to a common base unit and calculates the price per unit for each product. The cheapest option per unit is highlighted so you can easily see which product offers the best value.
The comparator supports common weight and volume units: kilograms (kg), grams (g), pounds (lb), ounces (oz), liters (L), milliliters (ml), and gallons (gal). When comparing products, the tool automatically converts all quantities to compatible base units (grams for weight, milliliters for volume) so you get an accurate comparison.
Yes. The tool handles unit conversions automatically. For example, you can compare a 500g package priced at $4 with a 1.5kg package priced at $10. The tool converts both to grams, calculates the price per gram for each, and highlights the cheaper option. You can compare weight units with weight units and volume units with volume units.
Comparing unit prices helps you make smarter purchasing decisions. A larger package is not always cheaper per unit, and a sale price is not always the best deal. By calculating the price per unit, you can objectively compare products regardless of package size, brand, or store. This can save you significant money over time, especially on groceries and household items.

Last updated: June 2026