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

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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

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

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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

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Excavation Calculator

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