Concrete Ramp Calculator

1. Enter the ramp run in feet, the horizontal length of the slope.
2. Enter the rise in inches, the height it climbs, and the width in feet.
3. Add a top landing length if there is a flat landing, and a 10 percent waste allowance.
4. Pick a bag size for a bag count, then read the cubic yards to order.

Here is what each result line means:

A concrete ramp calculator turns the run, rise and width of a ramp into the amount of concrete to order. It is built for a solid ramp, poured full from the base up to the sloped top, such as a threshold ramp, a driveway apron or an accessibility ramp on grade.

A solid ramp is a wedge, a triangular prism, so its volume is half of the run times the rise times the width. The tool adds an optional top landing, converts to cubic yards and bags and adds a waste allowance. To size a flat slab or path that meets the ramp, use the concrete slab calculator; for the mix, the concrete mix calculator.

Cut a solid ramp down the middle and the side is a right triangle: the run along the bottom, the rise up the back. A triangle is half of the rectangle around it, so the wedge is half of run times rise, and multiplying by the width gives the volume.

1. Convert the rise from inches to feet by dividing by 12.
2. Multiply run by rise by width and halve it for the wedge volume in cubic feet.
3. Add a top landing if there is one, taken as a solid block at the full rise height.
4. Add the waste allowance, divide by 27 for cubic yards and by the bag yield for a bag count.

For the binder in the mix, the cement calculator sizes the cement.

Suppose you are pouring a threshold ramp with a 12 foot run, a 24 inch rise and a 4 foot width, no landing, at 10 percent waste.

Calculation: the rise is 24 / 12 = 2 ft. The wedge is 0.5 x 12 x 2 x 4 = 48 cu ft. Adding 10 percent waste gives 52.8 cu ft, or about 1.96 cu yd, roughly 88 eighty-pound bags. The grade is 2 feet over 12, about 16.7 percent.

The lesson: a solid ramp uses a lot of concrete for its footprint, and at nearly two cubic yards this one is a ready-mix job.

Rise

The rise sets how deep the wedge is at the top, so a steeper ramp to the same run holds more concrete. A gentler, code-friendly slope over a longer run spreads the same rise thinner.

Run

Run is the base of the wedge and multiplies the volume. A long shallow ramp and a short steep one can hold very different amounts for the same rise.

Width

Width multiplies everything, so a wide vehicle ramp uses far more than a narrow walking ramp.

Landing

A solid top landing adds a full-height block of concrete. Include its length so you do not run short at the top.

There is more than one way to build a concrete ramp, and they use very different amounts of concrete.

If you are pouring a thin sloped slab over fill, size it as a slab by surface area and thickness; the concrete cost calculator in the related tools then prices either pour by the yard.

Ordering Concrete for a Ramp

Size the ramp in cubic yards and add waste before you order, so you can pour the whole wedge in one go.

Pricing a Small Threshold Ramp

For a short threshold or step ramp, the bag count shows how many bags to buy and whether hand mixing is realistic.

Checking the Grade

The tool reports the slope and surface length, so you can see the grade before you pour and compare it to the limit your project needs.

1. Sizing It as a Thin Slab

A solid ramp is a full wedge, not a thin slab, so estimating by surface area badly under-orders. Use the run and rise, which the tool turns into the wedge volume.

2. Mixing Up Rise Units

Enter the rise in inches and the run and width in feet, as the fields are labelled. Entering the rise in feet overstates a low ramp twelvefold.

3. Forgetting the Landing

A flat top landing is solid at the full rise height and can be a big share of the pour. Include its length.

4. Ignoring the Grade Limit

A ramp that is too steep fails its purpose. Check the reported grade against your project needs, and lengthen the run if it is too steep.

5. Treating the Estimate as a Design

Volume is not compliance. Slope, landings, edges and accessibility limits come from your code or an engineer, not from this tool.

The arithmetic is exact for a solid wedge; the usefulness depends on the run, rise, width and landing you enter.

A solid ramp is a wedge, so multiply the run by the rise by the width and halve it, then add any landing and divide by 27 for cubic yards. A 12 foot run rising 24 inches at 4 feet wide is 0.5 x 12 x 2 x 4 = 48 cubic feet, about 1.78 cubic yards before waste.

It depends on the run, rise and width. A 12 foot threshold ramp rising 24 inches at 4 feet wide is about 1.78 cubic yards, or 1.96 with a 10 percent allowance, roughly 88 eighty-pound bags. Enter your own dimensions above.

Because a solid ramp is poured full as a wedge, not as a thin slab. Even though you only see the sloped surface, the concrete fills the whole triangle underneath, which is half of the run times the rise across the width.

It depends on the use and the code; accessibility ramps are often limited to about a 1 in 12 slope, or 8.3 percent. This tool reports the grade from your run and rise so you can check it, but it does not set the limit.

Yes, if the ramp ends in a flat landing. Enter the landing length and the tool adds it as a solid block at the full rise height. Leave it at zero if the ramp meets an existing slab or floor.

A 12 foot threshold ramp is roughly 88 eighty-pound bags with waste, which is a lot to mix by hand, so a ramp this size is usually ready-mix. The tool gives the bag count for your ramp and bag size, rounded up.

Yes, and it uses far less concrete. A sloped slab over compacted fill is sized as a slab by surface area and thickness, not as a solid wedge. This tool sizes the solid-fill case; use a slab estimate for the slab-on-fill case.

No. The calculation runs entirely in your browser and nothing you enter is stored or sent anywhere.

• QUIKRETE Concrete Mix 1101 data sheet (QUIKRETE; bag yields 0.60, 0.45 and 0.30 cu ft).
• National Ready Mixed Concrete Association (NRMCA; ready-mixed concrete and ordering).
• American Cement Association (American Cement Association; concrete flatwork basics).