Perspective Grid Calculator

The horizon line represents eye level, and this calculator measures its position down from the top edge. At 50% (centre), the viewer is at a neutral height. A high horizon line (30-40% — near the top of the frame) creates a bird's-eye view looking down, so objects sit below your eye level. A low horizon line (60-70% — near the bottom) creates a worm's-eye view looking up, making objects appear taller and more dramatic.

For 2 and 3-point perspective, both horizon vanishing points should sit off the canvas — beyond its left and right edges. VPs crammed onto the page cause extreme foreshortening that looks distorted. As a rule of thumb, the separation between the two VPs should be at least 1.5 times the canvas width, which keeps your subject inside the cone of vision. This calculator places them 1.6 times the width apart, so each one lands a little beyond the opposite edge.

The cone of vision is the roughly 60° field (30° each side of your line of sight) in which a drawing reads as natural — anything outside it gets stretched. It is a fixed artistic guideline and does not change with lens choice, so this calculator always shows 60°. The separate "angle of view" figure is the photographic horizontal field of view of the focal length you enter on a full-frame 36mm sensor: about 40° at 50mm (a fairly tight, natural-looking view), wider at 35mm and narrower at 85mm. Use it to match a drawing to a reference photo, not as the cone of vision itself.

Use 1-point for looking straight down a road or corridor. Use 2-point for most scenes with buildings at angles. Use 3-point for dramatic upward or downward views of tall structures. Most drawings use 2-point perspective.