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Garden Steps Calculator — Rise, Going & Materials
Calculate step count from level change, tread and riser materials, foundation concrete and cheek walls.
Height difference between levels
Width of each step
Strip footing only — back-fill is hardcore
Height of each step (AD K max 220mm)
Depth of each tread (AD K min 220mm)
Estimates matching brick/block for both side walls
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How We Calculate This
This calculator determines the number of steps, materials and foundation concrete from the total level change between two areas. If the route needs step-free access, our UK access ramp calculator sizes a Part M compliant ramp for the same level change.
Step count
Number of Steps = ceil(Level Change / Rise)
Actual Rise = Level Change / Number of Steps
Total Going = Number of Steps x Going
Materials
A concrete strip footing at 150mm depth runs under the full staircase footprint (sized 100mm wider than the step each side). Brick or block risers are calculated from step width and rise height using UK coordinating sizes (225×75mm brick course, 450×225mm block course). The stepped void behind the risers is filled with compacted hardcore (MOT Type 1) rather than mass concrete, following standard UK garden-step practice. Cheek walls are optional side walls built in the matching masonry.
Frequently Asked Questions
The ideal rise for garden steps is 100-175mm with a going (tread depth) of 280-350mm. A comfortable formula is: 2 x Rise + Going = 550-700mm. For example, 150mm rise with 300mm going = 600mm, which is comfortable. Building Regulations Approved Document K (2013, England) sets a private-stair maximum rise of 220mm and minimum going of 220mm, but for external steps and stairs that form part of a dwelling its Table 1.1 Note 2 raises the minimum going to 280mm — so aim for at least a 280mm going outdoors. (Part K applies only to steps attached to the building; freestanding garden steps follow it as best practice.)
Divide the total level change by your chosen rise. For example, a 900mm level change with 150mm rises needs 6 steps. If the division doesn't give a whole number, round up and recalculate the actual rise to keep all steps equal. Unequal step heights are a serious trip hazard.
Yes, garden steps need a concrete strip footing (150mm deep minimum) on a compacted sub-base. This prevents settlement and movement. This calculator sizes the footing 100mm wider than the step on each side. On clay soils, consider 225mm depth to get below the frost zone. The void behind each riser is then filled with compacted hardcore (MOT Type 1), not mass concrete.
Cheek walls (side walls) are recommended for steps wider than 900mm and on slopes where soil could wash onto the steps. They also provide a handrail mounting point. Under Approved Document K a handrail is recommended on at least one side where the flight is under 1000mm wide, and on both sides if it is 1000mm or wider; separately, guarding is required in dwellings where the drop exceeds 600mm. Cheek walls are typically built in matching brick or block.
Brick risers with paving slab treads are the most popular UK garden step construction. Natural stone (York stone, sandstone) gives a premium finish. Timber sleeper steps suit informal gardens. Use non-slip treads and consider drainage — a slight fall (1:60) on each tread prevents standing water and ice.
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Last updated: March 2026
Verified against UK standards · estimates only, confirm with your supplier.