Electrical Reference Charts
Conductor, conduit, and grounding look-up charts for sizing and code checks.
Electrical
25 CHARTSConductor, conduit, and grounding look-up charts for sizing and code checks.
CONDUCTORS & AMPACITY
- AMPWire Ampacity ChartCu & Al ampacity at 60 / 75 / 90°C by size.NEC 310.16
- ×0.8Ampacity Correction & Adjustment FactorsAmbient & bundling derate multipliers.NEC 310.15(B)(1) & 310.15(C)(1)
- DIMWire Dimensions ChartDiameter & area by insulation type and size.NEC Chapter 9, Table 5
- Ω/kftWire Resistance ChartDC resistance & stranding by AWG / kcmil.NEC Chapter 9, Table 8
CONDUIT, RACEWAY & TRAY
- FILLConduit Size & Fill ChartUsable fill area by trade size, EMT to PVC.NEC Chapter 9, Tables 1 & 4
- LBConduit Bodies ChartLB, LL, LR, T & X decoded, with form profiles.NEC 314.16(C)
- CTFCable Tray Fill ChartAllowable tray fill by width, ladder & solid.NEC 392.22
- MAXTHHN Conduit Wire Capacity ChartSOONMax THHN counts per conduit type and size.NEC Chapter 9, Tables 1, 4 & 5
GROUNDING & BONDING
- GNDGround Wire Size ChartMinimum EGC size by breaker or fuse rating.NEC 250.122
- GECGrounding Electrode Conductor ChartGEC size from the service-entrance conductor.NEC 250.66
- MBJBonding Jumper Size ChartMBJ / SSBJ & grounded conductor by supply size.NEC 250.102(C)(1)
- TRAYCable Tray Grounding ChartTray metal area to serve as the EGC, by OCPD.NEC 392.60(A)
MOTORS & TRANSFORMERS
MOTOR CIRCUITS & STARTERS
- SZ 1NEMA Starter Size ChartSizes 00–9: max HP per voltage, plus amps.NEMA ICS 2
- 175%Motor Circuit Protection ChartMax fuse & breaker % of FLA, plus overloads.NEC 430.52 / 430.32
- MTRMotor Circuit Data ChartWire, fuse, breaker, starter & switch per HP.NEC 430 / NEMA ICS 2
- AC-3IEC vs NEMA Starter ChartAC-1–AC-4 duties and the NEMA trade-offs.IEC 60947-4-1
DISCONNECTS & FUSES
ENCLOSURES & RECEPTACLES
Plumbing
11 CHARTSFixture units, drainage sizing, and pipe look-up tables — IPC and UPC labeled.
DRAINAGE, WASTE & VENT
- DFUDrainage Fixture Unit (DFU) ChartDFU values per fixture, IPC & UPC side by side.IPC 709.1 / UPC 702.1
- DRNDrain Pipe Size ChartDrain & building-drain size from total DFU.IPC 710.1 / UPC 703.2
- BLDGBuilding Drain & Sewer Capacity ChartMax DFU on building drain & sewer, by slope.IPC 710.1(1) / UPC 703.2
- VENTVent Pipe Size ChartVent size from DFU and developed length.IPC 906.1 / UPC 703.2
- SLPDrain Pipe Slope ChartMinimum grade per pipe size, IPC & UPC.IPC 704.1 / UPC 708.1
- TRAPFixture Trap Size ChartMin trap & trap-arm size per fixture, IPC & UPC.IPC 709.1 / UPC 702.1
WATER SUPPLY SIZING
- WSFUWater Supply Fixture Unit (WSFU) ChartWSFU per fixture, with GPM demand conversion.IPC E103.3 / UPC 610
- GPMWSFU to GPM Conversion ChartDesign GPM from total WSFU, both system types.IPC E103.3(3)
- WTRWater Pipe Sizing ChartSupply pipe & meter size from WSFU and length.UPC 610.4 / IPC 604.3
- FLOWFixture Water Demand ChartMax GPM & GPF per fixture, code & WaterSense.IPC 604.4 / EPAct 1992
FUEL GAS & GREASE
- GASNatural Gas Pipe Sizing ChartPipe size from BTU load and longest run.NFPA 54 / IFGC 402
- FOGGrease Interceptor Sizing ChartSOONInterceptor size from fixture flow & retention.IPC 1003 / UPC 1014
HVAC & Mechanical
10 CHARTSDuct sizing, airflow, static pressure, and sheet-metal look-up tables.
DUCT SIZING & AIRFLOW
- CFMDuct Sizing ChartCFM per round duct size at design friction rates.ASHRAE Fundamentals
- DeRectangular to Round Duct Conversion ChartEqual-friction rect ↔ round duct equivalents.ASHRAE Fundamentals
- ΔPDuct Friction Loss ChartLoss per 100 ft by CFM and duct diameter.Darcy-Weisbach (computed)
- FLEXFlex Duct CFM ChartTaut flex vs rigid CFM, plus the slack penalty.LBNL / ADC / UL 181
- FPMAir Velocity ChartRecommended FPM for ducts, grilles & coils.ASHRAE / ACCA lineage
LOAD & SYSTEM RULES
ABOUT THESE CHARTS
These charts cover the numbers electricians look up mid-task rather than compute: conductor ampacities at 60°C, 75°C, and 90°C, usable conduit fill area by trade size, equipment grounding conductor sizes by breaker rating, grounding electrode and bonding jumper sizing, motor full-load currents, transformer overcurrent protection percentages, and the NEMA enclosure and plug-configuration references.
Every chart states its governing section of the National Electrical Code (NFPA 70) — Table 310.16 for ampacity, Chapter 9 for conduit and wire dimensions, 250.122 and 250.66 for grounding — and the full table is rendered on the page, not behind a search box or a login. Verify values against the code edition your jurisdiction has adopted; these are working references for licensed electricians, not a substitute for the code book or the AHJ.
When the answer needs computing instead of looking up — voltage drop on a specific run, ampacity after derating, fill for a specific wire mix — each chart links to the matching NORDIX calculator.
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