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Unit Price Comparator: Price per 100 g, 100 mL, or Piece
Compare two or three products by price per 100 g, per 100 mL, or per piece, and add shipping and coupons to compare the effective price.
Comparison
- Comparison unit
- JPY / 100 g
- Price basis
- Listed price only
- #1Item BCheapest
49.80JPY / 100 g
Price used: 498 JPY / Total size: 1,000g
- #2Item A
59.60JPY / 100 g
Price used: 298 JPY / Total size: 500g
Versus cheapest: +9.80 JPY / 100 g（+19.7%）
Only the listed price is compared. Shipping and coupons are excluded.
Unit prices are rounded to two decimal places, and the ranking uses that rounded value. Items with the same unit price share a rank.
Works well with
To work out the sale price of the item with the lowest unit price, try the discount calculator.
Compare different pack sizes on one unit
Enter a price and a pack size, and the tool ranks each item by price per 100 g, per 100 mL, or per piece. A 500 g bag and a 1 kg bag, or a 350 mL can and a 2 L bottle, are converted to the same unit before they are compared.
You can also compare the effective price with shipping and coupons included.
Open detailed notes
What a unit price is
A unit price is the price divided by the pack size, expressed for a fixed amount. Products with different pack sizes cannot be judged by the shelf price alone, so they are converted to a shared basis first. This tool shows weight per 100 g, volume per 100 mL, and countable items per piece. Sizes given in kg or L are converted to g and mL before the calculation.
Which units can be compared
Comparison works inside one group: weight (g, kg), volume (mL, L), or pieces. Comparing g with mL would require the density of each product, so it is not attempted. If the units you entered come from different groups, the tool says so instead of showing a ranking.
How the effective price treats shipping
In effective price mode the tool calculates price plus shipping minus discount. Shipping is added in full, as if each item were bought on its own. Splitting a single shipping fee across several items in one order is not calculated, so a combined order costs less per unit than shown here. The effective price never drops below zero.
Rounding and what counts as cheapest
Unit prices are rounded to two decimal places, and the ranking uses that rounded value so the displayed price and the rank always agree. Items with the same rounded unit price share a rank. The comparison unit and the price basis stay visible on screen, so you can check the conditions behind the cheapest label before you buy.
Use the Discount Calculator to work out a sale price, and the Tax Calculator to keep every item on the same tax basis.
Frequently asked questions
Are the prices and sizes I enter saved?
No. The comparison runs only in your browser, and prices, sizes, and item names are never sent to a server.
Can I compare units from different groups, such as g and mL?
No. Weight (g, kg), volume (mL, L), and pieces are separate groups. Converting between weight and volume needs the density of the product, so those units cannot be compared here.
How is shipping handled?
Shipping is added in full, as if each item were bought on its own. Splitting one shipping fee across several items is not calculated, so a combined order costs less per unit than shown.
How are unit prices rounded?
Unit prices are rounded to two decimal places, and the ranking uses that rounded value. Items that end up with the same unit price share a rank.
How many items can I compare?
Up to three items at a time. At least two of them need both a price and a size.
Is consumption tax included?
The price you enter is used as is. Enter tax-included prices for a tax-included unit price, and keep the same basis for every item you compare.
How do I enter a six-pack or a three-piece bundle?
Enter the size of one pack in the size field and the number of packs in the pack count field. For a six-pack of 500 mL bottles, enter 500 mL and a pack count of 6.