How is the stone count worked out?

Stones = round up (path length ÷ centre-to-centre spacing) + 1. Each spacing interval needs a stone, and the +1 places the final stone at the very end of the path. For a 5m path at 0.6m spacing that is ceil(5 ÷ 0.6) + 1 = 9 + 1 = 10 stones, before any spares.

How much sand do I need under each stone?

The sand figure covers a 20-30mm sharp-sand bed directly beneath each stone footprint only. Dig the bedding hole a little wider than the stone (20-30mm all round) for levelling room, so buy a touch more than the headline figure. On clay soil use a 30mm bed and a thin sub-base of grit to aid drainage.

What stone size and shape should I choose?

A 400mm round or 450mm square stone comfortably fits an adult foot; 600 × 400mm rectangles suit a fast walking path or a wider tread. Natural riven sandstone or limestone costs more than reconstituted concrete but weathers in better. Whatever the shape, set the top flush with the lawn so a mower can pass over it.

How far apart should stepping stones be?

Space stepping stones 500-600mm centre to centre, matching an average adult stride. Walk the route first and have someone mark each footfall — that gives the most natural spacing. Use a shorter ~450mm gap for children or older walkers, wider for tall, long-striding adults.

How do I lay stepping stones in a lawn?

Place the stone, cut around it with a half-moon edger, remove turf to the stone depth plus the sand-bed depth, add and firm the sharp sand, then bed the stone level with or slightly below the grass so the mower clears it.

Stepping Stone Calculator — Free Paving & Paths Tool

How We Calculate This

This calculator determines the number of stepping stones, sharp sand, and approximate cost for a garden path.

Stone count

Stones = ceil(Path length / Spacing) + 1. The +1 accounts for the final stone at the end of the path.

Sand bed

Each stone needs a sharp sand bed underneath (typically 20-30mm deep) to allow levelling and drainage. The calculator totals this from the stone footprint × bed depth × number of stones, using a bulk density of about 1,500 kg/m³ for sharp sand. The figure covers the area directly beneath the stones only — dig each hole 20-30mm wider than the stone for levelling room, so buy a little extra.

Estimated cost

Costs are indicative per-stone estimates for reconstituted-concrete stones (around £8 each for a 400mm round bought in bulk; natural riven stone is higher), plus sharp sand at roughly £4 per 25kg bag. Check current supplier prices for your area, as crate or pack quantities are usually cheaper per stone.

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.