Mercury is the closest planet to the sun. Its average distance from the sun is 57.91 million kilometers or 35.98 million miles. Like the other planets, mercury's orbit is elliptical or oval shaped. That's why the distance from the sun to the planet is often given as an average. The minimum distance, when mercury is closest to the sun, is about 46 million kilometers, 29 million miles or 0.397 au (astronomical units). The maximum distance is 70 million kilometers 44 million miles or 0.466 au. An astronomical unit (au) is the distance from earth to the sun so this offers a comparison.
The closest point of an elliptical orbit to the sun is called perihelion and the farthest point is called aphelion.