Pipe Bend Developed Length Calculator

Inputs

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Included bend angle swept by the pipe centerline.
°
Enter the bend centerline radius directly, or calculate it from pipe OD times a bend-radius multiplier.
Bend centerline radius, not inside radius.
in
Actual pipe outside diameter used to screen bend severity.
in
Straight length before the first tangent point.
in
Straight length after the second tangent point.
in
Available straight pipe length before bending or shop trimming.
in

Results

Default result
Edit inputs
Centerline arc length(L_arc)
9.4248in
Pass

Arc length = centerline radius x bend angle in radians.

Also computed

Developed cut length(L_dev)Pass21.425in

Developed cut length = inlet tangent + centerline arc + outlet tangent.

Chord between tangent points(C)8.4853in

Chord = 2 x R x sin(angle / 2).

Setback to PI(S)Pass6in

Setback from each tangent point to the point of intersection is R x tan(angle / 2).

Centerline radius used(R)6in

Radius is entered directly or computed as pipe OD x radius multiplier.

Radius / OD(R/OD)Pass3x

Centerline radius divided by actual pipe OD. Confirm bender minimum radius, ovality and wall thinning separately.

Inside curve radius(R_i)Pass5in

Inside curve radius = centerline radius - OD / 2.

Circular bend centerline R 90 deg chord outlet tangent inlet tangent Developed length is tangent in + centerline arc + tangent out. Final bend setup still depends on actual bender and pipe spec.
Method notes 3 notes
  • Formula: centerline arc length L_arc = R x theta, with theta in radians.
  • Developed cut length adds the straight tangents to the centerline arc: L_dev = T1 + L_arc + T2.
  • This is geometry only. It does not include springback, bender gain/loss marks, minimum tangent tables, wall thinning, ovality, weld gap, bevel, socket/thread engagement, code requirements or manufacturer-specific tooling limits.

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