Whether you are estimating on the spot or checking a result somebody else gave you, the elevation grade calculator is the quickest way to get from horizontal distance (“run”), vertical distance (“rise”) and atan to grade in percentage, angle of elevation and grade.
What Is the Elevation Grade Calculator?
The elevation grade calculator turns horizontal distance ("run"), vertical distance ("rise") and atan into grade in percentage, angle of elevation and grade, so you can order the right amount of material the first time.
Material estimates are where projects go over budget. Getting the quantities right before the delivery arrives is worth more than any discount on the order.
How to Measure for the Elevation Grade
Measure everything in the same unit and take the largest dimension you can reasonably use rather than the average. Formwork, ground conditions and cutting waste all push the real figure above the theoretical one.
Where a plan calls for a specific thickness, check it against local building regulations before you order. The calculator reflects the relationship, not the code.
Allowing for Waste and Errors
Order a little more than the calculation suggests. The gap between the theoretical quantity and what actually arrives on site is normally waste, spillage, over-excavation and uneven grading, and all of it comes out of the same budget.
Write the figures down and compare them with what you actually used on site. That is how you build an estimate you can trust for the next job.
A Worked Example
Working through an example, with horizontal distance ("run") set to 10, vertical distance ("rise") set to 5, atan set to 2, the calculator returns grade of 0.5, and grade in percentage of 0.5, and angle of elevation of 0.46365. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out grade in percentage?
Enter horizontal distance ("run"), vertical distance ("rise") and atan. The calculator then works through the relationship and reports grade in percentage, angle of elevation and grade.
What does the elevation grade actually calculate?
It takes horizontal distance ("run"), vertical distance ("rise") and atan and converts them into grade in percentage, angle of elevation and grade using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter horizontal distance ("run")?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Why does a small change in one value move the answer so much?
That happens when an output depends on a ratio, because dividing by a small number magnifies any change in it. Check the units first, then check whether the value you entered is in the range the relationship was designed for.
Can I use this for a quick estimate as well as a precise answer?
Yes. The calculator is built for quick checks, so round your inputs to a sensible number of significant figures and the result will be just as useful. If you need more precision, keep the same method and add digits to the inputs rather than adjusting the method itself.