BendMarks: Conduit Bender NEC

Shows its work. Every bend, fill, and voltage drop expands into the NEC formula with your exact numbers. 100% offline. One-time purchase, no subscription.

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 the answer. Every bend, every fill, every drop expands into the formula and a labeled diagram.

— FEATURES —
• Conduit Bending — offset, rolling offset, 3-point saddle, 4-point saddle, 90° stub-up, and kick bends with labeled diagrams and exact mark distances • Voltage Drop — single-phase and three-phase, copper or aluminum, with pass/fail vs. NEC 3% and 5% targets
• Conduit Fill — NEC Chapter 9 percentages with cross-section visualization for any wire mix
• Box Fill — NEC 314.16(B) calculations for conductors, devices, grounds, and clamps
• Show Your Work — every result expands the formula with substituted values and a plain-English explanation, so you learn the math as you use it
• Glove-Friendly — oversized tap targets, fraction-native input, sunlight high-contrast mode for the field
• Recents — last 20 calculations one tap away
• NEC Code Cycles — switch between 2017, 2020, and 2023
• Fully Offline — zero network calls, zero analytics, zero tracking. Your jobs stay on your phone.
• One-Time Purchase — $14.99 once. No ads. No subscription. No upgrades you have to buy later.

Built by people who believe an apprentice should never be handed a black box. Hand them BendMarks instead — it teaches every step.

Sources: Benfield's Conduit Bending and Fabrication, Ugly's Electrical References, NEC 2023 Chapter 9. All NEC values are facts 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.