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Crop Yield Calculator — Estimate Vegetable Harvest

Estimate harvest yields for common vegetables based on growing area.

How We Calculate This

Yield = Area x Yield per m² x Skill Factor. Average yields are based on UK growing conditions with typical varieties.

Skill factors: beginner 60%, average 85%, experienced 100% of optimal yield.

Plant counts use recommended RHS spacings (e.g. potatoes and cordon tomatoes ≈ 0.25 m² each, courgettes ≈ 1 m², carrots and onions ≈ 0.01 m²). Harvest window shows how long the crop typically produces for.

Yield figures are average UK allotment kg/m² ranges (RHS grow-your-own guides, growveg.co.uk and gardenuk.co.uk) — for example tomato 5-10, courgette 5-8, potato 2-5, carrot 3-5 kg/m². Treat results as a planning estimate, not a guarantee.

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.