BendMarks: Conduit Bending

The conduit and code calculator that shows its work.

Built for electricians, apprentices and journeymen who want to know why the math works, not just what the answer is. Every bend, every fill and every drop opens into the formula and a labeled diagram.

FEATURES

• Conduit bending: offset, rolling offset, 3-point saddle, 4-point saddle, 90 degree stub-up and kick bends, with labeled diagrams and exact mark distances
• Voltage drop: single-phase and three-phase, copper or aluminum, with pass or fail against the NEC 3% and 5% targets
• Conduit fill: NEC Chapter 9 percentages, with a cross-section drawing for any wire mix
• Box fill: NEC 314.16(B) for conductors, devices, grounds and clamps
• Show your work: every result expands into the formula with your own values substituted, plus a plain language explanation, so you learn the math while you use it
• Glove friendly: oversized tap targets, fraction-native input, and a high contrast sunlight mode for the field
• Recents: your last 20 calculations one tap away
• NEC code cycles: switch between 2017, 2020 and 2023
• Fully offline: no network calls, no analytics, no tracking. Your jobs stay on your phone.

FREE FOREVER, AND WHAT THE UNLOCK ADDS

Offset and 90 degree stub-up are free for good, with the same math, the same diagram and the same show your work drawer as the paid bends. Nothing is metered and nothing expires.

One payment unlocks the rest: rolling offset, both saddles, kick bends, the obstruction planner, apprentice drill mode, voltage drop, conduit fill, box fill, recents and share cards. It is not a subscription, so there is no renewal and nothing to cancel later.

Built by people who believe an apprentice should never be handed a black box.

Sources: Benfield's Conduit Bending and Fabrication, Ugly's Electrical References, NEC 2023 Chapter 9. All NEC values are cited to their section. This app is a learning and field reference tool, not a substitute for code review or professional judgment. Always verify against your local code and a licensed electrician.