Compare up to four pack sizes and see which one really costs less per kilo, litre or unit — in your browser.
Supermarket shelves show the price of a pack, not the price of what is inside it, and the two rankings rarely match. A 500 g pack at R$ 8.90 and a 1 kg pack at R$ 16.50 look like a clear win for the smaller one until you divide: the first costs R$ 17.80 per kilo, the second R$ 16.50 per kilo. The big pack is 7.3% cheaper for exactly the same product. This tool does that division for up to four packs at once, converts the units so the numbers are comparable, and marks the winner.
The method is deliberately plain. Every quantity is converted to a single base — grams to kilograms, millilitres to litres, counted items to one unit — and the price is divided by it. The saving shown against each losing pack is the difference in unit price divided by that pack's own unit price, which is the number you would say out loud: choosing the kilo pack saves 7.3% compared with buying the same weight in 500 g packs. Weight, volume and counted items are kept apart on purpose, because a tool that happily divided grams by litres would produce a confident number that means nothing, so mixed units are refused instead.
A lower unit price is a strong argument, not a verdict. Multi-buy offers change the arithmetic before you compare — three packs for the price of two is three packs at two packs' price, so type the total you actually pay and the total quantity you take home. Beyond that, the cheapest kilo is a bad deal if half of it spoils, if the family-size box does not fit the cupboard, or if the concentrated version needs half as much per wash as the diluted one next to it. Use the number as the starting point and let the rest of the decision be yours. Everything is calculated in your browser, so no prices or shopping habits are sent anywhere.
Unit price = price ÷ quantity converted to the base unit (kilogram for weight, litre for volume, one item for counted packs; grams and millilitres are divided by 1,000). Saving against a pack = (that pack's unit price − the best unit price) ÷ that pack's unit price × 100.
Divide the price by the quantity to get the price per kilo, per litre or per unit, then compare those figures. R$ 8.90 for 500 g is R$ 17.80 per kilo, more than the R$ 16.50 charged for a full kilo.
No. Larger packs are usually cheaper per unit, but a promotion on the smaller size regularly reverses it, and some products are priced almost flat across sizes. Comparing takes ten seconds and the answer is not always the one you expect.
Enter what you actually pay and what you actually take home: three 500 g packs for the price of two is R$ 17.80 for 1,500 g, which comes to R$ 11.87 per kilo.
Because weight and volume are different quantities and the ratio between them depends on the product. The tool compares weight with weight, volume with volume and counted items with counted items, and asks you to fix mixed units instead of inventing a conversion.
No. The comparison runs entirely in JavaScript on your device — nothing you type is sent to a server or stored.
Vai.la turns any URL into a short link with click statistics, QR Code and your own biolink.
Vai.la is not responsible for how the tools are used or for decisions made based on their results.