What is my elevation?

How this is measured

The figure above is the height of the ground where you are standing, above mean sea level, in metres and in feet.

It does not come from your phone. It comes from a digital elevation model — a worldwide grid of ground heights assembled from satellite radar — which we ask about the coordinates your device reported. Your phone supplies the where; the model supplies the how high.

That grid has a resolution, and it is roughly 90 metres across at these latitudes. So the number is the average height of a square about the size of a city block, not of the paving stone under your feet. On flat ground the two are the same to within a metre. On a hillside they are not: if the slope drops ten metres across that square, the model can only tell you the middle of it.

This is why the page prints feet to the nearest ten rather than to the nearest one. 1,352 ft would look like a measurement taken with an instrument. 1,350 ft is an estimate, which is what it is.

Why your phone disagrees with it

Open almost any other app and you will get a different number, often by tens of metres. Both cannot be right, and the disagreement is not a bug in either.

Your phone can measure altitude itself, from the same GNSS satellites it uses for latitude and longitude. That measurement is far worse than the horizontal one — typically two to three times the error, so a fix good to 5 metres sideways may be 15 metres out vertically, and a poor fix can be 50 metres out or more. The geometry is the reason: satellites are spread around you horizontally but only ever above you, so there is far less to triangulate against in the vertical.

There is a second, larger discrepancy underneath that one. Satellite altitude is measured against a mathematical model of the Earth's shape called an ellipsoid, and sea level is not on that ellipsoid. The gap between them varies from about −105 metres to +85 metres depending on where you are on the planet. An app that shows raw GNSS altitude without correcting for it can be a hundred metres out before any measurement error at all.

Some phones also have a barometer, which is more precise but measures air pressure — so it needs to be told the local pressure at sea level to mean anything, and that changes with the weather.

We print none of these. The ground height for your coordinates is a better-behaved number than any of them, and it is the one that answers the question people are actually asking.

What it does not tell you

It is the height of the ground, so it is not your height, and it is not the height of the floor you are on. Standing on the twentieth storey, this number is the same as it is in the lobby. There is no signal available to any app that would distinguish the two.

It is also only as good as the position underneath it. The accuracy figure beside the answer is the radius your device believes it is within — if that says ±2 km, then the elevation is for a square somewhere in a two-kilometre circle, and in hill country that is not a useful answer even though it is a true one. A wide fix means a wide answer, and this page will show you the width rather than hiding it.

If you want to know why an app should tell you that at all, we wrote about it.