How is slope calculated?

Slope % = (rise / run) × 100. Angle in degrees = arctan(rise / run). The calculator outputs both, plus the slope distance √(rise² + run²) and the ratio as X:1.

What's the ADA-compliant slope for ramps?

ADA maximum is 1:12 (8.33%). Per the calculator's notes, sidewalk cross-slope max is 1:48 (2%). Always confirm against the latest ADA standards and local code.

What's the difference between slope and grade?

They describe the same thing. "Slope" is often expressed as a ratio or angle; "grade" is usually a percentage. 1:12 slope, 8.33% grade, and 4.76° angle all describe the same incline.

What's a minimum drainage slope?

Per the calculator's notes: 1–2% away from a foundation is a typical residential minimum. Specific drainage requirements depend on surface, climate, and code.

How do I convert percent slope to degrees?

angle = arctan(slope_decimal) × 180/π. Quick references: 5% = 2.86°, 10% = 5.71°, 20% = 11.31°, 25% = 14.04°, 50% = 26.57°, 100% = 45°. The calculator handles the conversion automatically.

What's the maximum driveway slope?

Most municipalities cap residential driveway slopes at 20–25%. Steeper than 15% gets uncomfortable and risks low cars bottoming out at transitions. Always design vertical curve transitions at the top and bottom of steep driveways.

Slope & Grade Calculator

Convert between slope percentage, angle, and ratio for ramps and drainage.

Slope & Grade Calculator

Distance (ft)

Rise (vertical)

Slope %(%)

Results

Slope

Angle

Ratio (run per 1 rise)

Slope distance

Rise

Need Construction Business Software?

These calculators are even more powerful inside The Blocks. During takeoffs, material quantities are calculated automatically from your measurements — no manual entry needed.

Learn more about Digital Takeoffs, AI Estimates, and Cost Catalog.

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Manual markup tools
Cost estimating & budgets
Bid management & proposals
CRM & contact management

MonthlyAnnualSave 20%

Seats:

$119 per seat × 1$119/mo

Total

$119/mo

$1,428/yr

How to Use This Calculator

Formula

slope% = (rise / run) × 100angle = atan(rise / run) × 180/πratio = run / rise (as X:1)slopeDistance = √(rise² + run²)

Parameters

Rise: Vertical change. Enter either rise or slope %.
Slope %: If set, calculates rise from run and percentage.

Results

Slope %: Grade as a percentage.
Angle: Slope angle in degrees.
Ratio: Run per 1 unit of rise (e.g., 12:1).
Slope Distance: Actual distance along the slope.
Rise: Calculated or input vertical change.

Example

ADA Ramp Check

1 ft rise, 12 ft run

slope = (1/12) × 100 = 8.3%angle = 4.8°ratio = 12:1 (ADA compliant)slopeDistance = √(1 + 144) = 12.0 ft

Common Use Cases

ADA ramp compliance (max 1:12)
Drainage grade checking
Driveway slope estimation
Road and parking lot grading

Notes

ADA ramp max: 1:12 (8.33%). Sidewalk cross-slope max: 1:48 (2%).
Residential drain minimum: 1-2% away from foundation.
Driveway maximum: ~25%.
Roof slope categories: low-slope ≤2/12 (~17%, requires membrane), conventional 3/12–9/12 (most asphalt shingles), steep >9/12 (specialty fasteners and underlayments).
Common ramp ratios: 1:12 (ADA standard), 1:16 (better, preferred where space allows), 1:20 (gentle, exempt from some handrail rules).

Frequently Asked Questions

Estimating software for your trade

This calculator handles one material at a time. If you bid whole jobs, see how The Blocks handles takeoffs, estimates, and proposals for your trade.

Get in Touch

Zaur Zhanabekov

Sales

+1 347-962-1064 zaur@theblocks.app

Need Construction Business Software?

These calculators are even more powerful inside The Blocks. During takeoffs, material quantities are calculated automatically from your measurements — no manual entry needed.

Web access — desktop, tablet & mobile

AI-powered plan takeoffs

Manual markup tools

Cost estimating & budgets

Bid management & proposals

CRM & contact management

MonthlyAnnualSave 20%

Seats:

$119 per seat × 1$119/mo

Total

$119/mo

$1,428/yr

How to Use This Calculator

Formula

slope% = (rise / run) × 100angle = atan(rise / run) × 180/πratio = run / rise (as X:1)slopeDistance = √(rise² + run²)

Parameters

Rise: Vertical change. Enter either rise or slope %.
Slope %: If set, calculates rise from run and percentage.

Results

Slope %: Grade as a percentage.
Angle: Slope angle in degrees.
Ratio: Run per 1 unit of rise (e.g., 12:1).
Slope Distance: Actual distance along the slope.
Rise: Calculated or input vertical change.

Example

ADA Ramp Check

1 ft rise, 12 ft run

slope = (1/12) × 100 = 8.3%angle = 4.8°ratio = 12:1 (ADA compliant)slopeDistance = √(1 + 144) = 12.0 ft

Common Use Cases

ADA ramp compliance (max 1:12)
Drainage grade checking
Driveway slope estimation
Road and parking lot grading

Notes

ADA ramp max: 1:12 (8.33%). Sidewalk cross-slope max: 1:48 (2%).
Residential drain minimum: 1-2% away from foundation.
Driveway maximum: ~25%.
Roof slope categories: low-slope ≤2/12 (~17%, requires membrane), conventional 3/12–9/12 (most asphalt shingles), steep >9/12 (specialty fasteners and underlayments).
Common ramp ratios: 1:12 (ADA standard), 1:16 (better, preferred where space allows), 1:20 (gentle, exempt from some handrail rules).

Slope & Grade Calculator

Slope & Grade Calculator

Need Construction Business Software?

How to Use This Calculator

Formula

Parameters

Results

Example

Common Use Cases

Notes

Frequently Asked Questions

Estimating software for your trade

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Get in Touch

Slope & Grade Calculator

Slope & Grade Calculator

Need Construction Business Software?

How to Use This Calculator

Formula

Parameters

Results

Example

Common Use Cases

Notes

Frequently Asked Questions

Estimating software for your trade

Related Calculators

Stair Calculator

Excavation Calculator

Concrete Calculator

Get in Touch