The Range and Bearing Calculator is a simple but powerful tool designed to help amateur radio operators quickly determine the distance and heading to a QSO partner. This calculator gives you instant, accurate results based on your chosen grid locators. For the most accuracy, use 10 figure locators. It’s ideal for contesting and portable hilltop operation, and is especially useful for the higher microwave bands.
Range / Bearing Calculator
Enter two IARU (Maidenhead) grid locators — 6, 8, or 10 characters — to get the range and bearing.
Location Accuracy
The calculator works from the geometric centre of the locator you provide, so the precision of your input directly affects the accuracy of the range and bearing it returns. A 6‑character grid locator spans several kilometres, meaning your true position could be noticeably offset from the calculated centre. Using 8 characters tightens the area dramatically to a few hundred metres. For the highest precision, 10‑character locators reduce the uncertainty to only a few tens of metres, giving a more accurate position for microwave operators to share.
Microwave Ops: Use 10‑Digit Locators
Although the difference between 6‑, 8‑ and 10‑character locators only produces a small change in the numerical range and bearing for a calculator like this, the actual ground position a locator represents can vary dramatically. For microwave work, where we often use path profiles to check a path, using a full 10‑character locator is the best choice. Tools such as Mike Willis’s SRTM Path Profile rely on accurate start and end points; if your true operating position is on the crest of a hill, even an 8‑character locator can place you a hundred metres down the slope, significantly lower in elevation. A 6‑character locator is worse still—its centre might fall in a neighbouring valley or even on the next ridge entirely. Precision matters, and the extra locator detail ensures your path modelling reflects the site you’re actually using.
Microwave Path Profiles
If you want to explore different microwave paths, it’s worth taking a look at SRTM Path Profile: A Practical Walkthrough. That guide shows you how to install Mike Willis' SRTM Path Profile utility and how to generate accurate terrain profiles and calculations of losses between two sites to see whether a path looks viable. It's an excellent tool for evaluating portable operating locations.