There is no point reaching for a calculator that cannot show its working. This one starts from length of curve, horizontal distance of point x, horizontal distance of bvc, elevation of bvc, final gradient (g2), initial gradient (g1) and one way and reports horizontal distance of evc, horizontal distance of pvi and elevation of point x, so you can see how each answer follows from the numbers you entered.
What Is the Vertical Curve Calculator?
The vertical curve calculator turns length of curve, horizontal distance of point x, horizontal distance of bvc, elevation of bvc, final gradient (g2), initial gradient (g1) and one way into horizontal distance of evc, horizontal distance of pvi and elevation of point x, 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 Vertical Curve
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 length of curve set to 10, horizontal distance of point x set to 5, horizontal distance of bvc set to 2, the calculator returns elevation of point x of 100.3125, and elevation of pvi of 100.25, and elevation of evc of 100.75. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out horizontal distance of evc?
Enter length of curve, horizontal distance of point x, horizontal distance of bvc, elevation of bvc, final gradient (g2), initial gradient (g1) and one way. The calculator then works through the relationship and reports horizontal distance of evc, horizontal distance of pvi and elevation of point x.
What does the vertical curve actually calculate?
It takes length of curve, horizontal distance of point x, horizontal distance of bvc, elevation of bvc, final gradient (g2), initial gradient (g1) and one way and converts them into horizontal distance of evc, horizontal distance of pvi and elevation of point x 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 length of curve?
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.
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.
Do I have to fill in every field?
Only the fields a particular result depends on. If you leave one blank, the results that need it simply show a note instead of a number, and everything else still works.