Inputs
Example Data Table
| Scenario | Total Rise | Tread | Landing | Suggested Steps | Actual Riser | Total Run |
|---|---|---|---|---|---|---|
| Terrace connection | 600 mm | 300 mm | 0 mm | 4 | 150 mm | 1200 mm |
| Bed access step | 360 mm | 280 mm | 0 mm | 3 | 120 mm | 840 mm |
| Stepped path with landing | 750 mm | 320 mm | 600 mm | 5 | 150 mm | 2200 mm |
Examples are illustrative. Measure your site carefully before building.
Formula Used
- Step count (N):
N = round(TotalRise / TargetRiser)(then adjusted to fit limits and riser range). - Actual riser:
R = TotalRise / N - Total run:
Run = (Tread × N) + Landing - Slope length:
L = √(TotalRise² + Run²) - Angle:
Angle = arctan(TotalRise / Run) - Comfort check:
2R + Tis compared to common walking ranges.
How to Use This Calculator
- Measure the vertical height between your two garden levels.
- Select your units and enter the total rise.
- Set a target riser height, plus a min–max range.
- Enter tread depth and optional landing length.
- Choose step limits if space is constrained.
- Press Calculate to see results above the form.
- Download CSV or PDF for sharing and site notes.
Site Measurement and Layout
Accurate garden stairs start with a measured total rise and a straight reference line. Measure from finished lower grade to finished upper grade, not from temporary soil. Record several points to catch dips, then use the largest rise for safe clearance. The calculator converts units consistently, so your tape notes match outputs.
Selecting Comfortable Riser Height
Riser height controls effort and rhythm. Outdoor steps often feel best when risers stay within a practical range and vary as little as possible. When you enter a target and a min–max band, the calculator chooses a step count that keeps the actual riser close to the target while respecting your limits. If the result flags a warning, revise the step count or rise measurement.
Tread Depth and Run Planning
Tread depth governs footing, especially on wet pavers or timber. The total run equals tread times steps plus any landing length, helping you confirm the stair fits between beds, walls, or edging. If your tread is outside your comfort range, keep the tread fixed but consider adding a landing or widening the path so steps feel stable.
Slope, Drainage, and Outdoor Safety
The angle and slope percent summarize how steep the stair will feel. Steeper values can require handholds, textured surfaces, or additional landings. For planting areas, plan drainage away from risers to reduce washout and algae. The 2R + T comfort check helps balance rise and tread for an easy stride on mixed terrain.
Materials, Maintenance, and Documentation
Use the counts of treads and risers to estimate blocks, timbers, gravel, and fasteners. For timber steps, add allowances for end cuts and ground contact protection. For stone or concrete units, verify base thickness and compaction so risers remain uniform after settling. Save CSV and PDF outputs for crew notes, inspections, and future repairs. When using stepping stones, consider nosing alignment and joints. Small adjustments in tread depth can preserve symmetry without changing riser height, improving comfort over seasons and storms.
FAQs
What does total rise mean in garden stairs?
Total rise is the vertical height from the finished lower surface to the finished upper surface. Measure after grading, paving, or decking decisions so the riser calculation reflects real walking height.
Why can the suggested step count change from my target riser?
The tool searches nearby step counts to keep risers within your min–max range and close to your target. It also respects your step limits and optional preference for an even number of steps.
Does the calculator change my tread depth automatically?
No. Tread depth stays as entered. The calculator checks your tread against your preferred range and reports warnings, while total run updates so you can confirm space and add a landing if needed.
What is the 2R + T comfort value?
It combines two risers plus one tread to approximate stride comfort. Values outside common ranges can feel too steep or too flat, especially outdoors where footing and surface texture matter.
How should I use the landing length input?
Enter any flat section at the top, middle, or bottom that is part of the stair run. It is added to total run and affects slope angle, helping you plan safer breaks on longer climbs.
Can I use inches and still compare comfort ranges?
Yes. Internally, calculations use consistent units and convert results back to your selection. Enter matching ranges in inches, and the comfort and warning checks will remain meaningful.