Every dimension is centre of line to centre of line, in metres.
All dimensions in metres. Check current rules and venue requirements before marking.
Centre-to-centre means every measurement is taken to the middle of the painted or taped line, not its edge. The tape machine runs along that centre, so a 50 mm line sits 25 mm either side of the marked centre.
Tennis court dimensions (ITF) are taken to the outside edge of the lines. A 23.77 m court with 50 mm lines is therefore 23.72 m from the centre of one baseline to the centre of the other.
FIBA measures the 28 x 15 m court to the inside edge of the boundary lines, so the boundary lines sit outside those dimensions. With 50 mm lines the centre-to-centre length is 28.05 m.
Most courts are marked with 50 mm lines. Tennis allows 25 to 50 mm (baselines up to 100 mm), netball allows up to 50 mm and pickleball uses 2 inch (50 mm) lines. Change the line width and every dimension updates.