Door Hinge Placement Calculator
Calculate the optimal placement positions for door hinges based on door height, number of hinges, and standard carpentry guidelines (BHMA/ANSI standards).
Formula
Top hinge position (from bottom):
Ptop = H − T
Bottom hinge position (from bottom):
Pbottom = B
Span between top and bottom hinges:
S = Ptop − Pbottom = H − T − B
Equal spacing gap (for N hinges):
G = S ÷ (N − 1)
Position of hinge i (0 = bottom, N−1 = top) from bottom:
Pi = B + i × G
Where: H = door height, T = top offset, B = bottom offset, N = number of hinges.
Assumptions & References
- Hinge positions are measured to the center of the hinge along the door edge.
- Standard top offset: 5 inches from the top of the door (BHMA/ANSI A156.7).
- Standard bottom offset: 10 inches from the finished floor / bottom of door.
- Intermediate hinges are spaced equally between the top and bottom hinges.
- BHMA recommends a minimum 12-inch gap between any two adjacent hinges.
- Doors taller than 90" or heavier than 200 lb typically require 4 or more hinges.
- Residential doors (up to 7 ft / 84") commonly use 3 hinges; commercial doors use 3–5.
- References: BHMA ANSI A156.7, International Building Code (IBC), and standard carpentry practices.