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ComputeVerse.ai

Engineering computation platform

Every calculation and studyshows its method.

A free library of 74 electrical engineering calculators — plus linked engineering studies and professional PDF reports — for practicing engineers, EITs, consultants, and students, for preliminary and educational work. Every result comes with the complete worked solution: the governing equations, the numerical substitution, the stated assumptions, and the references behind them.

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Worked solutionsInteractive plotsLinked studiesPrintable PDF reportsShareable linksFree, no account

Ohm's law — try it now

Live

Resistance RR

60 Ω

Power PP

240 W

Worked solution

R=V/I=120/2=60 ΩR = V/I = 120/2 = 60\ \Omega
P=V×I=120×2=240 WP = V \times I = 120 \times 2 = 240\ \text{W}

Live — try different values. Every calculator works exactly like this.

Not just a calculator. A place to do engineering.

ComputeVerse grows with the work — from a quick answer to a documented study.

  1. 01

    Calculate

    74 free calculators across power, circuits, control, signals and instrumentation — each with inputs, the full worked solution, assumptions and references.

    Browse the library

  2. 02

    Save

    Create a free workspace and keep your calculations in projects — reopen any one exactly where you left off, same inputs, same results.

    Create a free workspace

  3. 03

    Link into a study

    Enter shared values once — system voltage, load, power factor — and let them flow through every calculation in dependency order. Change one value; the whole study updates.

    See how studies work

  4. 04

    Report

    Generate a clean, professional PDF — inputs, worked solutions, a single-line network diagram, assumptions, limitations, references and your own branding.

    See a study end to end

Engineering studies, not just calculators.

A study answers the set of questions that describe one system. Enter the inputs once; every step runs in dependency order with the full worked solution behind each number — and a single-line diagram of the actual configuration.

Power Systems Fundamentals

Low-Voltage Feeder Study

Feeder sizing end to end from one set of inputs — transformer full-load current, three-phase load current, voltage drop over the run, conductor ampacity after derating, and the reactive power for a target power factor — each showing its full worked solution.

5 linked calculations · 8 inputs entered once

Transformer Sizing & Full-Load Current Calculator · Three-Phase Power Calculator · Voltage Drop Calculator · Cable Ampacity & Sizing Assistant · Power Factor Correction Capacitor Sizing

Open the study

Transformers

Transformer Fault & Motor-Starting Study

Available fault current at a transformer secondary, from nameplate %Z and the utility's contribution — with symmetrical and asymmetrical duty from the combined X/R ratio, and the voltage dip a motor start causes on that same bus.

4 linked calculations · 8 inputs entered once

Transformer Sizing & Full-Load Current Calculator · Symmetrical Fault Current Calculator · Transformer Impedance & Short-Circuit Current Calculator · Motor Starting Current & Voltage Dip Estimator

Open the study

Electronics & General Electrical

4–20 mA Measurement Chain Study

One process value followed from transmitter to ADC code — loop current, sense-resistor voltage, converter LSB and dynamic range, and the quantization error at the code the reading lands on.

4 linked calculations · 5 inputs entered once

4–20 mA Loop Scaling Calculator · Ohm's Law Calculator & Power Wheel · ADC Resolution & LSB Calculator · ADC Quantization Error & SNR Calculator

Open the study
Browse all studies

The report

A report you'd be glad to hand over.

Every study and calculation can become a complete engineering report — inputs, full worked solutions, a network diagram, assumptions, limitations, applicability and references, with a preliminary/educational disclaimer. Free to generate as a PDF, with the ComputeVerse attribution.

Reports are preliminary engineering documents — not a substitute for licensed review or a professional stamp.

See an example report

ComputeVerse Pro

Available

Pay once. Yours for good. Every calculator, your saved calculations and the full standard PDF report stay free — Pro adds study templates, your own branding on reports, and a bigger workspace.

$15 one-time — founding pricing. Pay once, keep it for good: no subscription, no recurring charges.

  • Included

    Custom-branded reports

    Your logo, company details and client identity on every report — single calculations and full multi-step studies alike.

  • Included

    Engineering study templates

    Build a study from any published template — the low-voltage feeder, transformer fault and measurement chain studies — with every step linked in dependency order.

  • Included

    A bigger workspace

    More projects and studies, organised your way. Saving and reopening your work is free; Pro lifts the count.

  • Coming soon

    Save your own templates

    Coming soon — turn one of your finished studies into a reusable template and re-run it on the next job.

    Still in development — not part of the current unlock.

What a worked solution includes

The answer is the smallest part.

Most online calculators return a number and nothing else. Every calculator here returns the full record: the given quantities, the governing equation, the substitution, the result, the assumptions the method rests on, and the sources the formulas are drawn from. This is the voltage drop calculator at its default inputs — rendered live, not an image.

Voltage Drop Calculator

Three-phase feeder · 2/0 AWG copper · default inputs

Voltage drop (percent) 0.76%Within the 3% limit.

Worked solution

1. Conductor properties (per foot)

R, X from conductor tableR,\ X \text{ from conductor table}
R=0.0000967 Ω/ft,X=0.000043 Ω/ftR = 0.0000967\ \Omega/\text{ft},\quad X = 0.000043\ \Omega/\text{ft}

Representative values for THWN/THHN-class conductors in non-metallic conduit.

2. Effective impedance per foot

Zeff=Rcos⁡θ+Xsin⁡θZ_{eff} = R\cos\theta + X\sin\theta
Zeff=0.0000967×0.9+0.000043×sin⁡(cos⁡−1(0.9))Z_{eff} = 0.0000967 \times 0.9 + 0.000043 \times \sin(\cos^{-1}(0.9))
Zeff=0.0001058 Ω/ftZ_{eff} = 0.0001058\ \Omega/\text{ft}

3. Voltage drop (three-phase, k = √3)

VD=k×I×L×ZeffVD = k \times I \times L \times Z_{eff}
VD=1.732×80×250×0.0001058VD = 1.732 \times 80 \times 250 \times 0.0001058
VD=3.664 VVD = 3.664\ \text{V}

4. Voltage drop as a percentage

VD%=VDV×100VD\% = \dfrac{VD}{V} \times 100
VD%=3.664480×100VD\% = \dfrac{3.664}{480} \times 100
VD%=0.7634%VD\% = 0.7634\%

5. Receiving-end voltage

VR=V−VDV_R = V - VD
VR=480−3.664V_R = 480 - 3.664
VR=476.3 VV_R = 476.3\ \text{V}

Given

System
Three-phase
Conductor material
Copper
Conductor size
2/0 AWG
Load current
80 A
One-way run length
250 ft
Source voltage
480 V
Load power factor
0.9
Maximum acceptable drop
3%

Assumptions

  • Lagging (inductive) power factor assumed; a leading power factor would produce slightly less drop than shown.
  • Conductor resistance and reactance are representative THWN/THHN values in non-metallic conduit, not a substitute for the governing code table.
  • Balanced loading assumed for the three-phase case; steady-state conditions (not motor starting).

References

  • NEC 210.19(A) Informational Note No. 4 and 215.2(A) Informational Note No. 2 — recommended voltage drop limits
  • IEEE Std 141 (Red Book), Ch. 3 — Voltage Considerations
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Change any input on the calculator page — the worked solution recalculates with it.

How these calculators are prepared

A number you can check beats a number you have to trust.

Built and verified by an engineer

ComputeVerse.ai is built and maintained by a practicing electrical engineer, using modern tools — including AI — as an assistant. The engineering judgment, checking, and review are human; the tools help produce it faster.

Checked against published examples

Each calculator's method, equations, and worked solution are checked against published examples from the references it cites where possible before it ships. If a calculation can't be sourced and reproduced, it doesn't go live.

Honest about limits

These are preliminary and educational calculations, and every page says so — the assumptions and limitations are stated where you can read them, not buried in fine print.

74 calculators · 10 categories · with citations

What you can calculate

From Ohm's law to fault current.

Calculators across 10 areas — the calculations that recur in design work, studies, and coursework. The library grows steadily; each new calculator meets the same standard.

01 · Category

Power Systems Fundamentals

Three-phase power, per-unit, fault current, voltage drop, power factor correction.

e.g. Three-Phase Power · Per-Unit Conversion · Symmetrical Fault Current

5 calculators

02 · Category

Machines & Drives

Induction motor equivalent circuits, nameplate performance, torque-speed curves, starting, V/Hz drives.

e.g. Induction Motor Equivalent Circuit Solver · Induction Motor Performance from Nameplate · Induction Motor Torque-Speed Curve Generator

5 calculators

03 · Category

Transformers

Sizing, full-load current, impedance, and short-circuit contribution.

e.g. Transformer Sizing & Full-Load Current · Transformer Impedance & Short-Circuit Current

2 calculators

04 · Category

Cables & Protection

Ampacity, conduit fill, and overcurrent device coordination.

e.g. Cable Ampacity & Sizing Assistant · Conduit Fill · Overcurrent Protection Coordination Checker

3 calculators

05 · Category

Communication Systems

dB/dBm, path loss, link budgets, thermal noise, channel capacity, BER, AM/FM, filter response.

e.g. Decibel & dBm Converter · Free-Space Path Loss (Friis) · Link Budget

11 calculators

06 · Category

Control Systems

Transfer functions, poles and zeros, step response, Bode and Nyquist plots, Routh-Hurwitz, stability margins.

e.g. Transfer Function Analyzer · Pole-Zero Analyzer & s-Plane Plot · Step / Impulse / Ramp Response

13 calculators

07 · Category

Circuit Analysis & Fundamentals

Ohm's law, series/parallel networks, dividers, RC/RL/RLC, energy storage, AC impedance, RMS and crest factor, Thévenin/Norton, Δ–Y, and the Wheatstone bridge.

e.g. Ohm's Law Calculator & Power Wheel · Resistor Series/Parallel Network · Voltage Divider

13 calculators

08 · Category

Signals & Systems

Convolution, DFT/FFT spectra, Fourier series, sampling and aliasing, signal metrics, and LTI frequency and time response.

e.g. Convolution · DFT / FFT Spectrum Analyzer · Fourier Series

7 calculators

09 · Category

Digital Logic Design

Karnaugh maps, Boolean simplification, truth tables, SOP/POS, logic gates, number systems, flip-flop tables.

e.g. Karnaugh Map Solver (2–5 Variables) · Truth Table Generator · Boolean Expression Simplifier

7 calculators

10 · Category

Electronics & General Electrical

RC/RL/RLC time constants, three-phase rectifier output, battery sizing, and instrumentation & measurement tools.

e.g. RC/RL/RLC Time Constant & Resonance · Three-Phase Rectifier Output · Battery Energy Storage Sizing

8 calculators
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Who it's for

  • Practicing electrical engineers
  • EITs and PEs preparing studies
  • Students and educators learning the derivations
  • Anyone who needs a defensible preliminary calculation with its work shown

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A free quick-reference for practicing electrical engineers — base quantities, change of base, a worked example, and common base values. You'll also hear when new calculators are added: one or two emails a month, nothing else.

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One thing to know before you rely on a result: these calculators are for preliminary engineering and educational use. How to use them responsibly

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