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PASSPULL — Know before you pullPASSPULLKnow before you pull.

CONDUIT PULL CHECKER

One pull. Total confidence.Know before
you pull.

Check conduit fill and ampacity derating together.

NEC 2023 Code-backed results Free to use Built for electricians
BUILD YOUR PULL5 simple steps

THHN/THWN-2 · ½–2 in. conduitSupported inputs & limits

1

Conduit

Select the raceway type and size.

2

Conductors

Include every wire, including neutrals and grounds.

Conductor group 1
THHN/THWN-2
Equipment ground
THHN/THWN-2
3

Current-carrying conductors

How many conductors will carry current?

4

Termination temperature rating

Use the lowest rating of any connected equipment.

Ambient temperature 30°C / 86°F

No rooftop temperature adder or special installation corrections are included.

5

Load / circuit amps

Required load for each circuit conductor group.

A Compared with the lowest allowable ampacity.

Single conductors · standard runs over 24 in. · NEC 2023

YOUR PULL, CHECKED.EXAMPLE PULL

PASS

This pull meets the checked fill and ampacity limits.

Conduit fill

17.1%of conduit area
Within allowed limit

40% allowed · NEC Ch. 9, Table 1

Real ampacity

32 Aallowable after derating
30 A required32 A
Covers your 30 A load

310.15(C)(1) + Table 310.16

Within the checked limits.

Fill, derating, and terminations work together here. Ordinary small-wire protection: 30 A max.

A field check, not an inspection guarantee. Verify the adopted NEC edition, equipment listings, breaker selection, and local requirements with your AHJ.

Show the calculation

Fill: 0.1477 in² ÷ 0.864 in² = 17.09%. Allowed area: 0.346 in². Verdict uses unrounded areas.

#10 AWG: 40 A × 80% conductor adjustment × 100% ambient correction = 32 A. Capped at 35 A for 75°C terminations → 32 A.

Required: 30 A × 100% noncontinuous = 30 A. Every circuit group is checked against this load.

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BEFORE THE WIRE GOES IN

Conduit fill and ampacity derating calculator

PassPull checks how much space your conductors occupy, how conductor count and ambient temperature affect ampacity, and where equipment termination ratings limit the result. Use one NEC 2023 setup for all three checks.

Choose EMT, PVC Schedule 40, RMC or IMC; enter every conductor, the current-carrying count, termination rating and required load; then check the result. See the supported sizes and assumptions before relying on a setup.

The wires fit. Can they carry the load?

Space in the pipe and allowable current are different limits. Check both before deciding that a pull works.

Read the guide

Count conductors, not circuits.

The number used for heat adjustment is often different from the number used for physical fill.

Read the guide

90°C wire does not mean 90°C terminals.

The wire jacket and the equipment connections place different limits on a circuit.

Read the guide
Does PASS mean my installation will pass inspection?

It means your inputs meet the implemented checks within the supported scope. It does not evaluate the entire installation or replace your adopted NEC, equipment listings, and local inspector’s requirements.

Will a larger pipe fix an ampacity failure?

It can reduce the fill percentage. The same current-carrying count still receives the same adjustment factor. Try a suitable larger circuit conductor, or plan separate raceways for complete circuits and recheck each one.

Do I need an account to save or share?

No. Save up to 20 named pulls in this browser, copy a setup link, or download a field-check record. Local saves do not sync between devices. A shared setup must be checked again by its recipient.

FIELD CHECK · NEC 2023

An honest answer has a clear scope.

PASS means the entered arrangement meets the implemented fill, adjusted ampacity, termination and ordinary small-conductor protection checks under the stated assumptions. It is not a permit, stamped design, or guarantee of inspection approval.

Supported: EMT, PVC Schedule 40, RMC and IMC, ½–2 in.; conventional noncompact THHN/THWN-2 insulated conductors, copper #14–#2 and aluminum #12–#2; standard runs over 24 in.; ambient bands from 26–60°C.

Not evaluated: voltage drop, pulling tension, bend count, jam ratio, grounding-conductor sizing, bonding, box fill, raceway suitability, parallel conductor requirements, motor/HVAC exceptions, rooftop adders, or final breaker selection. Equipment grounds are counted for fill only.

Code edition and adoption vary by jurisdiction. NEC 2026 is not included. Verify against your legally adopted code and authority having jurisdiction (AHJ). The catalog and engine require independent qualified electrical review before public launch.

Read the full reference & scope
PASSPULL · Know before you pull.
PASSPULL — PASS (checked limits only)
1 in. EMT · NEC 2023
6 × #10 AWG copper THHN/THWN-2 · circuit
1 × #10 AWG copper THHN/THWN-2 · ground
Current-carrying: 6 · Termination: 75°C · Ambient: 30°C
Fill: 17.09%; allowed 40% (0.1477 / 0.346 in² allowed).
Lowest allowable ampacity: 32 A. Required: 30 A (noncontinuous).
Small-conductor protection cap: 30 A. Final breaker selection not evaluated.
#10: 40 A × 0.8 × 1 = 32 A, terminal limit 35 A → 32 A.

PASSPULL · NEC 2023
Conduit fill: Chapter 9, Table 1 (including Notes 3, 6 and 7), Table 4, Table 5.
Conductor adjustment: 310.15(C)(1).
Ambient correction: Table 310.15(B)(1)(1).
Base ampacity: Table 310.16.
Terminations: 110.14(C).
Small-conductor overcurrent protection: 240.4(D).
Continuous load sizing: 210.19(A)(1) / 215.2(A)(1), as applicable.
Field check only; verify adopted code, equipment ratings and AHJ requirements.
Not evaluated: voltage drop, ground sizing, bonding, box fill, bends/pulling tension, special circuits, rooftop adders, final breaker selection. Verify before installation.