ΔE 7.9, close: similar, with a visible difference side by side. Chestnut Brown is a little lighter, cooler than Waffen Red Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Chestnut Brown is a little lighter, cooler than Waffen Red Brown.
The same difference applies the other way round: Waffen Red Brown is a little darker, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Waffen Red Brown on the colour wheel See Chestnut Brown on the colour wheel
All matches: Waffen Red Brown equivalents · Chestnut Brown equivalents