Measure bank geometry, check angles, and size stone layers accurately for projects. Get area, volume, and weight outputs, plus clean downloads for planning records.
| Case | Rise (m) | Run (m) | Bank Length (m) | Thickness (m) | Waste (%) |
|---|---|---|---|---|---|
| Riverbank repair | 3.0 | 6.0 | 40 | 0.35 | 7 |
| Drainage channel | 1.5 | 3.0 | 25 | 0.25 | 5 |
| Coastal embankment | 4.0 | 10.0 | 60 | 0.45 | 10 |
Stable revetments start with accurate geometry. A flatter slope increases contact area and reduces unit stress on the lining, but it also increases material quantity. This calculator converts rise-run or H:V ratios into angle, slope length, and surface area so you can compare options quickly.
A ratio like 2:1 means two horizontal units for one vertical unit. For a 3.0 m rise, the run becomes 6.0 m and the slope length is √(6²+3²)=6.708 m. The corresponding angle is arctan(3/6)=26.6°. These values help crews set batter boards and check finished lines.
Surface area drives stone, mattress, or block quantities. Area equals slope length times bank length, then multiplied if you are lining multiple faces. For 6.708 m slope length and 40 m bank length, area is 268.3 m² before any multiplier. Use “0 = per meter” to estimate unit quantities for bidding.
When thickness is provided, volume is area times thickness. With 0.35 m thickness, 268.3 m² becomes 93.9 m³. Add a waste allowance for sorting, breakage, and placement losses; 7% waste produces 100.5 m³. This aligns well with practical ordering buffers on rock work.
Transport planning often needs weight. Using a typical rock unit weight of 26 kN/m³, 100.5 m³ corresponds to about 2,613 kN of stone. Convert to mass if needed using local gravity. This supports haul scheduling, stockpile sizing, and crane or excavator lift planning.
An allowable angle screen helps identify steep faces that may require benches, toe keys, or stronger linings. If your allowable is 30°, the 26.6° example passes. If your computed angle exceeds the limit, review geometry, erosion protection type, and site access constraints before finalizing.
The sliding and overturning fields are included as documentation placeholders. Different agencies compute stability using hydraulic loading, unit weights, pore pressure, and friction. Record your project’s required factors here so exported reports carry the same reference numbers used in design checks and approvals.
Start with measured rise from survey, pick a trial ratio, and check the resulting run and angle. Iterate until you balance right-of-way limits with stability. Then enter bank length and thickness to estimate quantities. Export the CSV for takeoff sheets and the PDF for daily reports. Include toe protection notes, rock class, and placement dates for consistent inspection records, and simplify closeout documentation later.
If bank length is zero, results are calculated for one meter of bank. This is useful for unit-rate estimating or comparing slope options without committing to a full project length.
Use one method. If you choose ratio, adding a rise simply scales the geometry to your actual height. Leave run empty when using ratio to avoid confusion.
The calculator uses θ = arctan(rise ÷ run), reported in degrees. The angle is measured above the horizontal, which matches common field layout and batter checks.
Thickness depends on stone size, underlayer, and design standard. Enter your specified placed thickness for a quick volume estimate, then confirm with your project drawings and specifications.
Waste covers breakage, rejection during grading, placement losses, and trimming. Typical allowances range from 5–10%, but adjust to your supply quality, access, and placement method.
No. Sliding and overturning factors are recorded for reporting only. Stability verification requires hydraulic and geotechnical inputs and the method specified by your governing standard.
Yes for geometry and area. Use the calculated area and your product’s thickness to estimate volume or units. Always confirm manufacturer details, toe conditions, and filter requirements.
Plan slopes carefully to protect banks and budgets today.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.