Think of a circle, not a bend
The R in 1000R stands for radius. The panel is a slice of a circle that size, measured in millimeters. A 1000R screen follows a circle with a radius of 39.4 inches (1 meter), and an 1800R screen follows one with a radius of 70.9 inches (1.8 meters). A smaller number is a tighter circle, so it's a stronger curve.
The radius also points at a seat. Sit at the center of the circle and every part of the screen is the same distance from your eyes. At 28 inches (70 cm) the circle around your eyes has a radius of 700 mm, which is tighter than even an 800R curve. Sit closer than the radius and the edges are a little farther from you than the middle is. Sit farther back and they're a little nearer.
How deep the curve really is
The rating alone doesn't tell you how much the glass bends. Depth does: the gap between the screen's edges and its middle. On a 34-inch 21:9 panel:
- 1000R bows 3.1 in (78 mm) and spans 45 degrees
- 1500R bows 2.1 in (52 mm) and spans 30 degrees
- 1800R bows 1.7 in (44 mm) and spans 25 degrees
Going from 1800R to 1000R adds 1.3 in (34 mm) of depth. That's the difference between a hint of curve and a real wrap.
The same number feels different on other panels
A rating describes the circle, and a wider panel covers more of it. 1500R on a 27-inch 16:9 monitor bows just 1.2 in (30 mm) and spans 23 degrees. The same 1500R on a 49-inch 32:9 monitor bows 4.6 in (118 mm). That's a much deeper curve from the same rating.
So the choice matters more on wide panels. A 49-inch 32:9 screen at 1000R spans 69 degrees, a wrap a 27-inch monitor would never need.
Matching the curve to your seat
The rating closest to your seat distance keeps the whole screen about the same distance from your eyes. Someone sitting 31 inches (80 cm) from the screen is at the center of an 800 mm circle, so 800R fits that seat and 1800R is a much lighter curve. A seat at 5.9 feet (1.8 meters) is the center of an 1800R circle, but a desk seat is usually well inside that. So 1800R reads as gentle and 1000R as strong.
If you're not sure, the Curved Monitor Visualizer draws a curve next to a flat panel of the same size.