Landscape grade is the vertical change in elevation divided by the horizontal distance, multiplied by 100. Cut and fill estimates add another measurement: the depth of soil to remove or place across an area.
Use the landscape grading calculator below to check a slope, find the drop over a patio, or estimate cut and fill volumes.
Choose Slope & Grade for a rise, run or elevation calculation. Choose Simple Cut or Fill for an approximately uniform area. Choose Grid Cut/Fill when existing and proposed elevations vary across the project. Optional material and hauling inputs help translate those estimates into loose soil and truckloads.
These are planning estimates from the measurements and assumptions you enter. They do not establish a drainage design, an acceptable construction slope, or final excavation quantities.
Rise or fall is the vertical change between two points. Run is the horizontal distance between them. Percent grade expresses that change for every 100 units of horizontal distance. A 5% grade changes elevation by 5 feet over 100 horizontal feet, or 5 centimeters over 100 horizontal centimeters.
Use the same units for the vertical change and horizontal run before dividing. A 6-inch drop over 20 feet is 0.5 ÷ 20 × 100 = 2.5% fall. Dividing 6 by 20 without converting inches to feet would give the wrong result.
The run is not the length of a tape laid along sloping ground. The USGS explanation of slope uses horizontal distance and distinguishes percent grade from the slope's angle.
Choose a clear starting point and ending point. For a small preliminary check, a level line between points can help you measure vertical change while keeping the run horizontal. For elevations gathered with surveying or leveling equipment, follow the instrument's measurement procedure and keep every point on the same reference.
Record which end is higher. If the start elevation is 100 feet and the end is 99 feet, the change from start to end is −1 foot, meaning a fall. Over a 40-foot horizontal run, that is a 2.5% falling grade.
A local reference such as 100 feet can be convenient, provided it is used consistently. Do not combine a relative job-site elevation with an elevation from a different reference and assume the numbers are comparable. A single line also does not describe every high spot, depression or cross-slope across a site.
The same slope can be written three ways. Here, ratios always mean horizontal:vertical. A 4:1 slope has four units of horizontal run for one unit of vertical change.
| Grade magnitude | Horizontal:vertical ratio | Angle magnitude |
|---|---|---|
| 1% | 100:1 | 0.57° |
| 2% | 50:1 | 1.15° |
| 5% | 20:1 | 2.86° |
| 10% | 10:1 | 5.71° |
| 25% | 4:1 | 14.04° |
| 100% | 1:1 | 45° |
These are conversions, not recommended construction slopes. A 100% grade is 45 degrees, not 90 degrees. The calculator identifies whether the slope rises or falls in your chosen direction.
For a known target grade, multiply horizontal run by the grade written as a decimal:
Required drop = horizontal run × grade ÷ 100
Suppose a patio concept uses a 20-foot run and a 2% fall. The calculation is 20 × 0.02 = 0.4 feet, or 4.8 inches of drop. If the starting elevation is 100 feet, the ending elevation is 99.6 feet.
In metric units, a 6-meter run at the same grade needs 0.12 meters, or 120 millimeters, of drop.
The 2% value is an arithmetic example. The appropriate slope depends on the surface, design, drainage outlet and applicable requirements. A drainage slope calculator can work out the fall; it cannot decide where water should discharge or size a drainage system.
Cut means removing ground above the proposed soil surface. Fill means placing material where the existing ground is below that surface.
For an approximately uniform area:
Volume = horizontal area × average vertical depth
With area in square feet and depth in feet, the result is cubic feet. Divide by 27 for cubic yards. With square meters and meters, the result is cubic meters. One cubic yard is approximately 0.7646 cubic meters.
For a rectangle, area is length × width. For a circle, area is π × radius². Use a measured area if the footprint does not match those shapes. The average depth must represent the whole area; a depth taken only at the deepest spot will overstate a uniform-area estimate.
A rectangular area measures 30 feet by 20 feet and needs an average of 6 inches of fill.
| Step | Calculation |
|---|---|
| Area | 30 × 20 = 600 square feet |
| Depth in feet | 6 ÷ 12 = 0.5 feet |
| Placed volume | 600 × 0.5 = 300 cubic feet |
| Cubic yards | 300 ÷ 27 = about 11.1 cubic yards |
That is the space the placed soil must occupy. It does not automatically mean ordering 11.1 loose cubic yards. The volume delivered and the volume after placement can differ.
An approximately uniform rectangular cut area measures 40 feet by 25 feet, with an average cut depth of 9 inches.
40 × 25 × 0.75 = 750 cubic feet, or about 27.8 bank cubic yards of excavation. “Bank” means the soil's volume before it is disturbed.
This example is a grading-area calculation, not a complete pool-hole takeoff. It excludes excavation working space, the pool shell, steps, changing bottom profiles and other details unless those are represented in the supplied dimensions and depths. Pool water volume is a different calculation; see how to calculate pool gallons.
One average depth can hide what happens between the high and low sides of a project. Grid Cut/Fill lets you enter existing and proposed elevations at measured points across a rectangle.
The starting grid has four cells and nine measurement points. Measure the horizontal spacing, then enter an elevation at each point. Use a single proposed elevation for a level target, or proposed elevations by point for a changing target surface.
The calculator divides each cell into triangles and assumes the elevation difference changes linearly within each triangle. Where the difference crosses zero, it separates the modeled cut and fill portions before adding volumes. The displayed grid shows which points require removal, placement or no change.
Consider a 10-meter by 10-meter area that changes evenly from 1 meter of cut along one edge to 1 meter of fill along the opposite edge. The middle crosses the proposed grade. Each half has an average depth magnitude of 0.5 meters across 50 square meters:
The geometric difference is zero, but there is still material to excavate and place. Its suitability and volume after compaction determine whether additional material must come in or leave.
A grid estimates the surface between measurements. It cannot reveal an unmeasured ditch, abrupt wall, buried material or sudden change in grade. Use appropriate surveyed information and a more detailed terrain model when the project requires them.
Material changes volume as it is excavated and placed. Labeling the state helps keep a takeoff and an order consistent.
| State | Meaning | Typical use in this calculator |
|---|---|---|
| Bank / in place | Material before excavation | Cut quantity |
| Loose | Excavated or delivered material before compaction | Hauling volume |
| Compacted | Material after placement and compaction | Fill yield and adjusted balance |
Swell describes an increase in volume after excavation. If a job-specific assumption is 20% bank-to-loose swell, 100 bank cubic yards becomes 120 loose cubic yards.
Shrinkage, as used here, compares compacted volume with the original bank volume. With 10% bank-to-compacted shrinkage, those 100 bank cubic yards yield 90 compacted cubic yards. This is not the same as specifying a percentage of maximum dry density in a compaction requirement.
These percentages illustrate the calculation; they are not soil recommendations. Use project-specific information. FHWA earthwork guidance emphasizes geotechnical recommendations and the need to distinguish available material from material unsuitable for fill.
Reusable excavation can supply some or all of the fill. If only part of the soil is suitable, a project may need to export unsuitable material while importing suitable fill. A zero geometric balance does not resolve that material question.
Calculate truckloads from loose volume and the truck's usable capacity for that material:
Loads = loose volume ÷ usable capacity, rounded up
For 120 loose cubic yards and 12 usable cubic yards per load, the estimate is 10 loads. For 121 loose cubic yards, it is 11 loads. The usable capacity must account for actual payload constraints; this volume calculation does not check truck weights or legal limits.
If you enter prices, keep the units explicit: material or disposal cost per cubic yard or cubic meter in the stated material state, and hauling cost per load. The calculator totals those items only.
When you are ready to move from individual measurements to a property design, GIS can shorten project setup. In Structure Studios software, enter the address in Stage 1: Project Information to bring available aerial imagery and surveyed terrain data into your project. Terrain is generated from the address's elevation data so you can begin with site context already in place.
Review coverage and capture date, especially where the property has changed. GIS downloads use parcel credits. See how GIS Data works.
Continue designing landscape and hardscape projects in VizTerra, or outdoor living spaces in Vip3D, with Pool Studio available for projects that include a pool, spa, or water feature.
GIS data is not a promise that a property's present condition has been field-verified for your construction project. Confirm the information needed for design, engineering and construction decisions.
A grading plan uses a small set of terms precisely, and mixing two of them up changes the quantity you order. These are the ones that come up on almost every project:
Use this tool for preliminary quantities and arithmetic checks. Work involving drainage, structural fill, retaining walls, slope stability, grading near structures, or code-dependent elevations may require surveyed data, engineering or local review.
Confirm what the proposed elevation represents. Finished paving, its base, the soil subgrade and a planting surface are different levels. Account separately for material layers, stripping, working space and other allowances that your entered geometry does not include.
The calculator cannot size drainage systems, verify permits, identify underground conditions or establish that a slope is safe. It makes the chosen assumptions visible so you can decide what information the next stage needs.
Divide vertical elevation change by horizontal run, then multiply by 100. Use matching units and identify whether the ground rises or falls from the starting point.
In this calculator, it means four horizontal units for one vertical unit. That equals a 25% grade and an angle of about 14.04 degrees.
No. You also need the area's size and the existing and proposed surfaces, or a representative average cut/fill depth. A percentage alone does not tell you where those surfaces lie.
High areas may need excavation while low areas need material. Equal geometric totals do not mean no earthwork, and material suitability or compaction can change the hauling requirements.
No. Enter measurements in this calculator. Address-based project setup is a separate GIS feature in Structure Studios software; follow the GIS link above to see the workflow.
Divide cubic feet by 27. A 600 square foot area with 0.5 feet of fill is 300 cubic feet, or about 11.1 cubic yards. One cubic yard is approximately 0.7646 cubic meters.
Working out a different number on the same project?
Use the pool gallon calculator for water volume, the paver calculator for surface materials, and the landscape material calculator for soil, mulch, and aggregate.
A slope you work out in the calculator shapes decisions well beyond drainage, from where a patio steps down to whether the design needs a retaining wall.
In VizTerra, you work through those decisions inside the design. You can use Smart Data to pull displacement, the earth to add or remove when you build at height, straight from the project, and it updates when you change the design.
The calculator is a separate tool for checking slopes and cut and fill from the measurements you enter. It doesn't import into VizTerra, so keep its results with your project.
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