Why compare cost per m² rather than total cost?

Products come in different pack sizes and coverage rates. Cost per m² normalises prices so you can fairly compare different options.

How do I work out my coverage area?

Check the product label for coverage per bag or unit. Alternatively, use our Coverage Rate Calculator to work it out from depth and area.

Should I always choose the cheapest per m²?

Not necessarily. Quality, durability, and suitability matter too. A slightly more expensive option may last longer or look better.

How do I convert per m² to per sq ft?

Divide the per m² cost by 10.764 to get cost per square foot.

Why is cost per m² useful for comparing materials?

Different materials come in different bag sizes, weights, and prices. Cost per m² at the same depth gives a fair comparison between products and suppliers.

GardenCalcs.uk

Cost Per Square Metre Calculator — Compare Garden Material Prices

Work out cost per square metre for comparing garden materials.

Total Cost (Material A)

Total price you pay for this material (e.g. £250 for a bulk bag of gravel or a pack of paving slabs)

Area Covered (Material A)

Ground area this quantity covers — from the product's stated coverage (e.g. 1 bulk bag of 20 mm gravel ≈ 12 m² at 50 mm deep)

Compare with a second material

How We Calculate This

The basic figure is Cost per m² = Total Cost ÷ Area in m², giving a standardised unit price you can compare across products and suppliers.

Under Advanced Options you can refine it. Delivery is added to the total cost, and a waste / cutting-loss percentage reduces the usable area you actually cover. The full formula is therefore: Cost per usable m² = (Total Cost + Delivery) ÷ (Area × (1 − Waste%)). For example, a 20 m² order with 10% cutting waste only covers 18 usable m², so the real cost per covered m² is higher than the headline price suggests.

The comparison mode evaluates two materials side by side. Both options are normalised the same way — delivery added and area reduced by the same waste factor — so the difference shown is a genuine like-for-like saving rather than an artefact of one option being adjusted and the other not.

Cost per sq ft is provided for reference using the conversion factor of 10.764 sq ft per m² (1 m² = 10.7639 ft², since 1 ft = 0.3048 m exactly).

Frequently Asked Questions

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Last updated: February 2026

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