Vertical Curve Calculator
Enter entry grade, exit grade, PVI station, PVI elevation, and curve length to compute K-value, high/low point, and a full station-elevation table.
Curve Inputs
Positive = uphill, negative = downhill
Must be greater than zero
Curve Summary
K-Value
ft/% (or m/%)
Grade Change
%
Rate of Change
%/unit length
| Point | Station | Elevation |
|---|
Station-Elevation Table
| # | Station | Elevation | Grade (%) |
|---|
Enter curve parameters on the left and click Calculate.
Summary
Enter entry grade, exit grade, PVI station, PVI elevation, and curve length to compute K-value, high/low point, and a full station-elevation table.
How it works
- Enter the entry grade (g1) and exit grade (g2) as percentages (e.g. +3 or -2).
- Enter the PVI station (Point of Vertical Intersection) and its elevation.
- Enter the curve length — must be positive and in the same units as the station.
- The calculator computes PVC and PVT stations and elevations, the K-value, and locates the high or low point.
- A station-elevation table is generated at every 25-unit interval across the curve.
- Switch between feet and meters; the math is identical — only the unit label changes.
Use cases
- Design sag and crest curves meeting AASHTO stopping-sight-distance K requirements.
- Verify vertical alignment from road survey notes.
- Compute drainage low-point stations for inlet placement.
- Check rider comfort on sag curves using the K-value threshold.
- Generate an elevation table for field stakeout of a new road.
- Compare alternate curve lengths for a given grade break.
- Teach highway geometric design to engineering students.
Frequently Asked Questions
Last updated: 2026-06-11 ·
Reviewed by Nham Vu