SalevaWhat this calculator does
Two suppliers quote for the same rice. One offers a 5 kg bag, the other a 10 kg bag, at prices that are hard to compare in your head. The unit price settles it: what does one kilogram cost in each? This calculator takes up to four packs or offers, works out the price of one unit in each, and marks the cheapest, with how much more the others cost.
How to use it
- Choose what the goods are measured in. Every pack must use the same measure.
- For each pack, enter how much is in it and what it costs. The name is optional and only helps you read the result.
- The cheapest per unit is marked. The others show how much more they cost for the same amount.
A worked example
A 5 kg bag of rice costs Rs 1,450 and a 10 kg bag of the same rice costs Rs 2,800.
1,450 ÷ 5 = Rs 290 a kg · 2,800 ÷ 10 = Rs 280 a kg
The 10 kg bag is cheaper by Rs 10 a kg. The 5 kg bag costs about 3.6% more for the same rice. Whether that saving is worth it depends on how fast you sell 10 kg, which is the next question.
Put everything in the same unit first
The sum only works when every pack is measured the same way. Convert before you type.
| You have | Convert to | How |
|---|---|---|
| 750 g and 1 kg | grams | 1 kg = 1,000 g |
| 500 ml and 1.5 litres | ml | 1.5 litres = 1,500 ml |
| A dozen and a tray of 30 | pieces | 1 dozen = 12 pieces |
| A carton of 24 packs of 200 g | grams | 24 × 200 = 4,800 g |
When the cheapest unit price is the wrong choice
The lowest price per unit is the best buy only if everything else is equal. It often is not.
- Will it sell before it expires? A big pack at a low unit price is a loss if a quarter of it is thrown away.
- Can you spare the cash? Buying three months of stock to save 3% ties up money you may need for something that sells faster.
- Is it really the same quality? Compare like with like: the same grade, the same brand, the same freshness.
- What does delivery cost? Add transport and loading to the pack price before you compare.
- What are the payment terms? A supplier who gives you two weeks to pay may be worth a slightly higher price.
Using it on the selling side
The same sum helps when you set prices for different sizes on your own shelf. Customers expect the larger pack to be a little cheaper per unit. If your 1 kg pack works out cheaper per gram than your 5 kg pack, the large one will not sell, and a sharp customer will notice. Run your own sizes through the calculator when you price a new product.
Questions
Can I compare a price per dozen with a price per piece?
Yes. Choose pieces, then enter 12 as the quantity for the dozen and 1 for the single piece.
How do I include a "buy 10, get 1 free" offer from a supplier?
Enter the quantity you receive, 11, and the price you pay for 10. The unit price then includes the free one.
Should I add tax and transport?
Yes, if they differ between the offers. Add them to each pack's price so that you compare what the goods cost you on your shelf.
Related reading
- Buying well: order quantities, supplier credit and purchase records for a small shop
- How to price products in a small shop: cost, margin, rounding and when to change
- How to manage inventory in a small shop without spending your evenings counting
Saleva keeps the cost of every purchase by supplier, so you can see who was cheapest last time. Get the free Android app.