Free Tools
Trade Exam Calculators
Free reference tools for every trade — the same calculators built into our exam prep apps, available free on the web.
Voltage Drop Calculator
NEC-compliant voltage drop for single and three-phase circuits. Checks compliance with NEC 210.19(A) for any wire gauge and run length.
NEC Wire Size Recommender
Enter load, distance, and voltage — get the minimum AWG or MCM that keeps voltage drop within NEC limits. Full table from 14 AWG to 500 MCM.
Ohm's Law Calculator
Solve for voltage, current, resistance, or power from any two known values. Includes all 12 Ohm's Law formulas.
Conduit Fill Calculator
Calculate NEC conduit fill percentage. Supports EMT, IMC, RMC, and PVC. THHN/THWN wires #14–4/0. Instant compliance check.
OSHA Fine Calculator
Estimate OSHA penalty amounts by violation type, gravity, and employer size. Updated with 2024 penalty limits.
Fire Alarm Battery Calculator
Calculate minimum battery Ah per NFPA 72 §10.6.7. Standby + alarm current with 20% derating factor. Occupancy presets for residential, commercial, high-rise, and healthcare.
Backflow PSID Calculator
Enter field test PSID readings for DC, RP, PVB, or SVB assemblies — instant pass/fail per USC and AWWA M14 criteria. Includes quick-reference threshold table for all assembly types.
NEC Box Fill Calculator
Calculate minimum cubic-inch box volume per NEC 314.16(B). Enter conductors by AWG, devices, grounding conductors, and clamps — see required fill and matching standard box sizes instantly.
EMT Drug Dose Calculator
Practice weight-based drug calculations for NREMT exam. Covers epinephrine, adenosine, amiodarone, naloxone, and more.
Hazmat Placard Lookup
Enter any UN number (e.g. UN1203) and get the DOT placard class, proper shipping name, packing group, and hazard description instantly.
Crane Load Ratio Calculator
Calculate load-to-capacity ratio and rigging weight. Know your working load limits before you lift.
Refrigerant Charge Calculator
Estimate refrigerant charge by system tonnage and refrigerant type. Covers R-410A, R-22, R-32, and R-134a.
Real Estate Commission Calculator
Calculate gross commission, agent split, and net proceeds for any home sale. Essential for real estate license exam math questions.
Glasgow Coma Scale (GCS) Calculator
Score a patient's GCS from eye opening, verbal, and motor responses. Instant severity classification — minor, moderate, or severe TBI.
OSHA Fall Clearance Calculator
Calculate total fall clearance distance for shock-absorbing lanyards and SRLs per OSHA 1926.502. Pass/fail based on anchor height and lanyard type.
Pipe DFU Calculator
Calculate total drainage fixture units and minimum drain pipe size per IPC 2021 Table 710.1. Select fixtures and quantities for instant pipe sizing.
Phlebotomy Order of Draw
Interactive blood draw tube sequence per CLSI GP41. Click any tube for additive, purpose, common tests, and required mix inversions.
Pool Chemical Calculator
Calculate pool volume in gallons, free chlorine dosing (liquid or granular), and pH adjustment with muriatic acid or soda ash. CPO and AFO exam prep.
Coinsurance Calculator
Calculate insurance payouts, coinsurance penalties, and out-of-pocket costs using the standard P&C formula. Includes step-by-step exam breakdown. Essential for the Insurance P&C license exam.
NMLS Mortgage Calculator
Four calculators in one: PITI monthly payment, front/back-end DTI ratios, LTV and PMI thresholds, and a full amortization schedule. The exact mortgage math scenarios on the NMLS SAFE Act exam.
One-Rep Max Calculator
Estimate your 1-rep max from any set with the Epley and Brzycki formulas, plus training-load percentages. Core programming math for the NASM, ACE, and ISSA personal trainer exams.
GRM & Cap Rate Calculator
Compute gross rent multiplier, capitalization rate, and implied value with the income-approach formulas. Essential math for the real estate appraisal exam.
Broker Math Calculator
Total commission, seller's net proceeds, and the net-to-list price needed to net a target. The high-frequency math on the real estate broker license exam.
Forklift Load Center Calculator
See how a longer load center derates a truck's safe capacity and check a load against limits. A core stability concept on the OSHA forklift certification exam.
Coming Soon
Cooling Load Timer
2-stage cooling timer based on FDA requirements — tracks 135°F→70°F in 2 hrs and 70°F→41°F in 4 hrs for food safety compliance.
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