FreeConstruction · Earthworks

Grade and slope converter

Convert between percent grade, degrees, H:V ratio and inches per foot, with rise over a distance.

Free for the civil engineer role. No account needed.

Get every civil engineer tool · $10.20 a month

Your numbers

Value entered asHow the slope is written on the plan.Slope valueE.g. 2 for 2%, 3 for a 3:1 side slope, 0.25 for 1/4 in per ft.Horizontal distance (ft)Distance for the rise / fall result.

For the code check and stake sheet4 more, filled with typical values

What the slope is forPicks the code limit to check against.Elevation at the start (ft)Benchmark or finished elevation at the first stake.Stake spacing (ft)Distance between grade stakes. Widened if the run would need more than 10.DirectionWhether the grade goes down or up from the first stake.

Grade and slope converterForge by Norventus

How it works

Press Calculate to convert the slope.

The straightedge, tilted to the slopeHinge, quadrant, jack and height gaugeVial: the bubble runs to the high endPress Calculate and the straightedge rises to your slope, the bubble runs to the high end and the readout gives the percent grade, the degrees, the ratio and the rise, worked out by the tool.

Result

Ready when you are.Enter your numbers and press Calculate.

References

Check the work against these

A pass or fail against the ADA, building, plumbing or OSHA limit for what the slope is for, every common limit at once, ramp runs, and a grade stake sheet, with sources. Numbers in the result and in the plain-words read point here.

1
Guide to the ADA Accessibility Standards, Chapter 4: Ramps and Curb RampsGuide
US Access Board
Ramp runs no steeper than 1:12 with a 30 in maximum rise per run (405.2, 405.6), cross slope no steeper than 1:48 (405.3), and walking surfaces steeper than 1:20 treated as ramps.
2
International Building Code 2021, Chapter 18 (Section 1804.4 Site grading)Code
International Code Council (ICC Digital Codes)
Ground next to a foundation falls at least 5% (1 in 20) for 10 ft; swales and impervious surfaces within 10 ft at least 2%; 2% ground slope where climate or soil allows. Check the edition your jurisdiction adopted.
3
International Plumbing Code 2021, Table 704.1 Slope of horizontal drainage pipeCode
International Code Council (ICC Digital Codes)
Minimum drain slope: 1/4 in per ft (2%) for pipe 2-1/2 in and smaller, 1/8 in per ft (1%) for 3 to 6 in. Local plumbing codes may differ.
4
Appendix B to Subpart P of Part 1926, Sloping and benchingCode
OSHA
Maximum allowable excavation slopes under 20 ft deep (H:V): Type A 3/4:1, Type B 1:1, Type C 1-1/2:1; flatter where there are signs of distress or surcharge loads.

Your history with this tool

Nothing yet

Every result you calculate is kept here, so you can open yesterday's numbers on the next job. It stays on this device; use Save to My work to keep a result in your account.

Want it on every device? Make a free account and save runs to My work.

Go deeper

When this answer isn't the whole job

Pro sheetPremiumCompaction lifts and roller timeNumber of lifts, roller passes and hours to compact a fill area.In the role plan · see an example →Pro sheetPremiumCut and fill volume (average end area)Cut, fill and net earthwork between cross-sections using the average end area method.In the role plan · see an example →

Used by

Equipment operator Foreman and site lead Civil engineer

Grade and slope converter

Your numbers

Result

Check the work against these

Nothing yet

When this answer isn't the whole job

Applied Intelligence, three ways.

Watch TowerFor Business

BeaconFor Professionals

ForgeFor your Work