How the Unit Price Compare calculator works

The core idea behind this calculator is very simple: instead of looking at total package price, we calculate the price per one unit and then compare those unit prices side by side. The “unit” can be anything as long as you keep it consistent — grams, kilograms, milliliters, liters, ounces, pieces and so on.

For each product, we compute:

• Unit price = Total price ÷ Quantity

For example:

• Product A: $4.00 for 1kg of rice → unit price = 4.00 ÷ 1 = $4.00 per kg.
• Product B: $7.50 for 2kg of rice → unit price = 7.50 ÷ 2 = $3.75 per kg.

Even though Product B has a higher total price, it offers a lower cost per kg, which means it’s the better deal if you’re going to use all of it.

Many stores and online shops use different sizes for the same product to make deals look attractive. A huge family-size pack might look like the smartest choice, but sometimes the “regular” size quietly has a lower unit price. By converting everything into price per 1 unit, the calculator strips away all that confusion.

You can also use the tool for:

• Comparing regular vs. bulk packs.
• Checking whether a “buy 2 get 1 free” promo is truly cheaper.
• Comparing subscription refills vs. one-time purchases.
• Comparing different brands with different pack sizes.

Once the calculator knows the unit price of each product, it looks at the cheapest and most expensive options and estimates how much more you’d pay by picking the worst-value option. It then turns that gap into a simple savings percentage so you can see whether the difference is tiny or huge:

• 0–10%: Almost the same – choose based on taste or brand.
• 10–25%: Noticeable – the better-value option is worth considering.
• 25%+: Big savings – you can keep a lot of money over time by choosing the best deal.

Imagine two detergent packs:

• Pack A: $8.99 for 1.2L → unit price ≈ $7.49 per L.
• Pack B: $10.99 for 2L → unit price ≈ $5.50 per L.

The difference is about $1.99 per liter. If your household uses roughly 10L of detergent each year, picking Pack B saves nearly $20 per year on just one product. Multiply that across groceries, cleaning products and pantry staples, and the annual savings can quietly become very large.

This is why unit price comparisons are a favorite trick of budget pros: the math is simple, but the impact compounds over time.

Frequently Asked Questions

• Do all products need the same unit?

  Yes, for a fair comparison you should use the same unit type for each product (for example, all in grams or all in liters). If one pack is 1kg and another is 500g, convert them into the same unit before entering: 1kg = 1000g.

• Can I compare “piece” items like eggs or cans?

  Absolutely. If you’re buying eggs, soda cans, or anything that comes as separate pieces, use “piece” as the unit and enter the number of items in the pack. The calculator will show you the price per piece and highlight which pack is cheaper.

• Does cheaper per unit always mean better?

  Not always. A cheaper unit price is great, but only if you’ll actually use the product. If a huge bulk pack expires before you finish it, you might waste food or money. Also consider taste, quality, storage space and how often you really use that item.

• How can I use this tool for online shopping?

  When shopping online, scroll down to find the “pack size” (like 750ml, 500g, 24-pack, etc.), then copy the price and size into the calculator. You can quickly compare similar products from different brands or retailers to decide where you get the most value.

• Why does this matter if the difference is only a few cents?

  Tiny differences add up over time. If you save a few cents on 20–30 items across every grocery trip, that can become dozens or even hundreds of dollars saved each year – without sacrificing your lifestyle.

• Share screenshots showing how “special offers” can still be more expensive per unit.
• Run challenges like “guess which is cheaper per 100g” before revealing the result.
• Use it alongside discount, tip and budget tools to build a full money-saving toolkit.