Courgettes yield: how much is usable after prep (AP to EP %)
Courgettes: about 93% usable going whole to trimmed (ends off), with a published range of 86–98%. That is a cost factor of 1.08: for every kilo you need ready to use, buy 1.08 kg as purchased.
Yield by preparation stage
| Stage | Average | Range | What is lost | USDA item |
|---|---|---|---|---|
| Whole courgette → flesh and skin (ends off) | 93% | 86–98% | Ends | 2446 |
| Whole courgette → peeled flesh | 82% | 74–90% | Ends and skin | 2448 |
| Trimmed → sliced | 98% | 98–99% | Slicing loss | 2449 |
| Ready to cook → steamed (all summer squash) | 88% | 69–99% | Net losses | 2451 |
| Ready to cook → boiled (all summer squash) | 81% | 66–94% | Net losses | 2452 |
| Frozen sliced courgettes → boiled | 73% | 65–82% | Net losses | 2456 |
Yields multiply: 93% × 98% ≈ 91% for whole → sliced. You never add the losses together.
Courgettes lose very little to the knife and more in the pan, because they are mostly water. Cost a courgette side on the cooked weight.
Prep notes
Top and tail, then cut to the size the dish needs. Salting slices for 20 minutes draws out water before grilling or frying, so they colour rather than stew; the weight you lose there is water, not food.
What the yield does to the cost
Courgettes, 5 kg at £6.49 (JJ Foodservice, 10 Oct 2026) is £1.30 a kilo as purchased. At 82% usable that is £1.58 per usable kilo.
Worked example: a 120 g side of steamed courgettes needs 146 g as purchased, costing 19p. Costed on the bought weight it would read 16p, so the costing would be 18% light: 3p a portion, or £3.42 over 100 portions.
| Usable courgettes needed | Buy (as purchased) at 93% |
|---|---|
| 1 kg | 1.08 kg |
| 5 kg | 5.38 kg |
| 10 kg | 10.75 kg |
Use 93% in the yield calculator →
Typical uses
Ratatouille, griddled courgettes, fritters, pasta, soups and vegetarian bakes.
Storage and the trim
Refrigerate dry and use within about five days; soft spots spread quickly. Ends are waste; overgrown courgettes with large seeds can be grated into soup.
Yield source: USDA Agriculture Handbook No. 102, Food Yields Summarized by Different Stages of Preparation (Matthews and Garrison, USDA Agricultural Research Service, 1975), Table 1, items 2446, 2448, 2449, 2451, 2452, 2456 (US samples of whole courgettes (zucchini); the cooked rows cover all summer squash). Prices as stated, read on 10 Oct 2026. Your own case is the real number: weigh it in the yield calculator.
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