Door Hinge Jig Calculator in Woodworking by Robert 6th April 20181st August 2019 0 comments Use this simple hinge jig calculator to work out quickly the internal size you need to make your jig so you can use a router to machine your hinge cut outs. Premium hinge leaf measurements: 3″ the leaf is generally 76mm x 19mm | 4″ the leaf is generally 102mm x 30mm Enter Hinge Leaf Length mm Enter Hinge Leaf Width mm Enter Router Guide Bush Diameter mm Enter Router Cutter Diameter mm Collet – Cutter Difference mm Collet – Cutter Difference ( Half ) mm Hinge Jig Opening Length – Internal dimension for router guide to follow mm Hinge Jig Opening Width – Internal dimension for router guide to follow mm Handy Guides Or PDF Jig making collar and cutter guide External Guidance FD30 FD60 Hardware Installation : Forza Doors FD30 Fitting Instructions : Jeldwen Doors