Price Per 100g Calculator
Find the true cost of your groceries. This calculator helps you compare products of different sizes by showing a standardized "price per 100g".
Enter the item's Total Price and its Total Weight in grams (g) to see how much it costs per 100g. This is the ultimate tool for smart shopping and value comparison.
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Understanding Price Per 100g
Why is Price Per 100g a Useful Metric?
Grocery stores often sell the same product in many different package sizes. A larger box might seem like a better deal, but that's not always true. Calculating a standard unit price, like the cost per 100 grams, allows for a true "apples-to-apples" comparison.
By using the price per 100g, you can instantly see which product offers more for your money, regardless of brand or package size. It removes the guesswork and helps you make informed purchasing decisions.
How the Calculation Works
The formula is simple and effective:
Price Per 100g = (Total Price / Total Weight in Grams) * 100
This calculator first determines the price of a single gram and then scales it up to 100 grams, a common standard for unit pricing on store shelves worldwide.
10 Real-Life Examples
Click on an example to see how the calculation works in different scenarios.
Example 1: Comparing Two Cheeses
Scenario: You see two blocks of cheddar cheese.
- Cheese A: $3.50 for 250g. Calculation: ($3.50 / 250) * 100 = $1.40 per 100g.
- Cheese B: $5.00 for 400g. Calculation: ($5.00 / 400) * 100 = $1.25 per 100g.
Conclusion: Cheese B is the better value, even though its initial price is higher.
Example 2: Bulk Bin Nuts
Scenario: You scoop a bag of almonds from a bulk bin.
Known Values: Total Price = $6.25, Total Weight = 450g.
Formula: ($6.25 / 450) * 100
Result: The almonds cost approximately $1.39 per 100g.
Example 3: Box of Cereal
Scenario: A family-size box of cereal is on sale.
Known Values: Total Price = $4.99, Total Weight = 720g.
Formula: ($4.99 / 720) * 100
Result: The cereal costs approximately $0.69 per 100g.
Example 4: Jar of Spices
Scenario: A small jar of paprika seems expensive.
Known Values: Total Price = $3.29, Total Weight = 45g.
Formula: ($3.29 / 45) * 100
Result: The paprika costs $7.31 per 100g. This high unit price is common for spices and herbs.
Example 5: Coffee in Pounds (lb)
Scenario: A 1lb bag of coffee costs $9.99.
1. Convert Weight: First, convert pounds to grams. 1 lb ≈ 454g.
2. Known Values: Total Price = $9.99, Total Weight = 454g.
3. Formula: ($9.99 / 454) * 100
4. Result: The coffee costs $2.20 per 100g.
Example 6: Large Tub of Yogurt
Scenario: A large 1kg tub of Greek yogurt.
1. Convert Weight: First, convert kilograms to grams. 1 kg = 1000g.
2. Known Values: Total Price = $5.75, Total Weight = 1000g.
3. Formula: ($5.75 / 1000) * 100
4. Result: The yogurt costs $0.58 per 100g.
Example 7: Deli-Sliced Turkey
Scenario: You buy sliced turkey from the deli counter.
Known Values: Total Price = $8.45, Total Weight = 350g.
Formula: ($8.45 / 350) * 100
Result: The deli turkey costs $2.41 per 100g.
Example 8: Bag of Pasta
Scenario: A standard 500g bag of pasta.
Known Values: Total Price = $1.89, Total Weight = 500g.
Formula: ($1.89 / 500) * 100
Result: The pasta costs $0.38 per 100g.
Example 9: Shampoo Bottle (Liquids)
Scenario: A 400ml bottle of shampoo costs $6.00. For liquids like water, shampoo, or milk, 1ml is approximately equal to 1g.
1. Convert Volume to Weight: 400ml ≈ 400g.
2. Known Values: Total Price = $6.00, Total Weight = 400g.
3. Formula: ($6.00 / 400) * 100
4. Result: The shampoo's unit price is $1.50 per 100g (or per 100ml).
Example 10: Can of Tuna
Scenario: A can of tuna often lists a "drained weight". Use that for the most accurate comparison.
Known Values: Total Price = $1.50, Drained Weight = 120g.
Formula: ($1.50 / 120) * 100
Result: The tuna costs $1.25 per 100g.
Frequently Asked Questions
1. How do I use this calculator?
Enter the total price of the item in the first field and its total weight in grams in the second. Click the "Calculate" button to see the price for every 100 grams.
2. What if my item's weight is in Kilograms (kg)?
You must convert it to grams first. The conversion is easy: 1 kilogram = 1000 grams. For a 1.5 kg item, enter `1500` into the weight field.
3. Can I use this for items weighed in Pounds (lb) or Ounces (oz)?
Yes, but you must convert the weight to grams first. Use these common conversions: 1 pound ≈ 454 grams and 1 ounce ≈ 28.35 grams.
4. Does the calculator work with any currency (e.g., €, £, ¥)?
Yes. The calculation is the same regardless of the currency. Although the label shows a '$', the math works for any currency. The result will be in the same currency unit you used for the price.
5. What happens if I enter text or leave a field blank?
The calculator will show an error message. It requires valid, positive numbers in both fields to perform a calculation.
6. Is this calculator only for food?
No! You can use it for any product sold by weight, such as pet food, laundry detergent powder, crafting supplies, or bulk hardware like nails and screws.
7. How should I handle liquids sold in milliliters (ml) or liters (L)?
For most water-based liquids (like milk, juice, soft drinks, shampoo), the density is very close to 1 g/ml. You can treat milliliters as grams (e.g., 500ml ≈ 500g). For liters, remember 1 liter = 1000ml ≈ 1000g.
8. Why does the result have two decimal places?
The result is automatically rounded to two decimal places (e.g., $1.52) because this is the standard format for pricing and currency.
9. What's a good strategy for using this in a store?
When you see two similar items, quickly enter the price and weight for each one. The one with the lower "Price Per 100g" is the more economical choice at that moment.
10. For canned goods, should I use the total weight or the drained weight?
For the most accurate comparison of the actual food content, it's best to use the drained weight if it's provided on the label. This represents the weight of the solid food without the packing liquid.
