Can a higher unit price mean a cheaper shop?
Yes, when whole-pack rounding changes how many packs you need. Fictional example: for a 1,000 g target, a 750 g pack at £3 costs £0.40 per 100 g, but two packs cost £6. A 1,000 g pack at £4.50 costs £0.45 per 100 g, yet one pack meets the target for £4.50. Pack A wins on unit price; Pack B costs £1.50 less for this shop.
These are invented demonstration prices, not current retailer prices or a product recommendation.
How the comparison works
Each option is calculated independently: packs = round up(target ÷ usable yield); spend = packs × price; surplus = packs × yield − target. Prices use integer pennies and quantities use fixed decimal precision, so an exact multiple does not gain a phantom extra pack.
Unit prices are displayed per 100 g, 100 ml or one piece, rounded to three decimal places in pounds. Winner comparisons use unrounded values, so close prices may look equal after display rounding. Zero target means zero packs and tied total spend, even when unit prices differ.
Only compare like with like
Choose one basis for the target and both usable yields. Do not compare raw grams with cooked grams, drained weight with gross weight, or different-size pieces as though they are interchangeable. This calculator does not convert between those quantities or verify that the products meet the same need.
Use the actual price you qualify for, including any required membership. This version supports one identical-pack price for each option, not multibuy tiers, delivery fees, minimum orders or loyalty eligibility. A low price does not prove dietary suitability, quality, affordability or safe storage.
Questions people ask
Does the pack-value calculator use live supermarket prices?
No. You enter the price and usable yield from the exact current product. The defaults are a fictional example. No supermarket feeds, memberships or paid price-comparison services are used.
Can I compare pieces instead of grams?
Yes. Choose Pieces and enter whole-number piece counts. Both products must provide genuinely comparable pieces. The tool cannot tell whether one biscuit, scone or sandwich piece is equivalent to another.
Can I combine Pack A and Pack B in one order?
Not in this version. It compares an all-A purchase with an all-B purchase for the same target. It does not optimise mixed packs or predict what surplus you will actually use.
Sources and assumptions
- The Unflustered Host — editorial method — transparent assumptions and arithmetic checks; all prices and yields are entered by the user, not supplied by a price feed