Comparison

Ohms Law Calc. vs DC Wire Sizer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Ohms Law Calc.

This app provides a comprehensive suite of electrical calculations, including Ohm's Law, voltage drop, wire sizing, and impedance. It also offers numerous converters for various electrical units and parameters, aiding in circuit design and analysis.

Highlights
  • Ohm's Law calculations
  • Voltage drop calculator
  • Wire size calculator
  • Impedance calculations (R, L, C)
  • Electrical unit converters
  • Power and current conversions
  • Circuit design tools
Features
Read full description

Ohm's Law Calc. consists of 60 Electrical Calculators with Formulas and Circuits and 16 Electrical Converters. • Voltage Calculator • Current Calculator • Resistance Calculator • Power Calculator • Voltage Drop Calculator • Wire Size Calculator • DC Generator Calculator • Transformer Calculations (Voltage & Current) Impedance Calculators Calculate impedance for combinations of resistors (R), inductors (L), and capacitors (C) in both series and parallel configurations: • R and L in Series / Parallel • R and C in Series / Parallel • L and C in Series / Parallel • R, L and C in Series / Parallel Power and Current Conversions • kVA to Amps (Single Phase & Three Phase) • Amps to kVA (Single Phase & Three Phase) • Single Phase & Three Phase Power Calculators • Horsepower Calculators (DC, Single Phase, Three Phase) Efficiency and Power Factor Tools • Efficiency Calculators (DC, Single Phase, Three Phase) • Power Factor Calculators (Single Phase & Three Phase) Energy Storage Calculators • Energy Cost Calculator • Energy Storage Calculators (Resistance, Inductance, Capacitance) Circuit Design Tools • Star-to-Delta and Delta-to-Star Conversions • Inductive & Capacitive Reactance Calculators • Resonant Frequency Calculator • Inductor and Capacitor Sizing Equations Component Calculations • Series and Parallel Calculators for Resistance, Inductance, and Capacitance • Unknown Resistance and Capacitance Calculators (Series & Parallel) More Calculations • Neutral Current (3-Phase Unbalanced Loads) • Characteristic Impedance (Parallel & Coaxial) • Transformer Calculator • Voltage Divider Calculator Illumination Calculators • Luminous Intensity Calculator • Luminous Flux Calculator • Solid Angle Calculator Electrical Converters • Field Strength Converter • Electrical Potential Converter • Resistance and Resistivity Converters • Conductance and Conductivity Converters • Capacitance and Inductance Converters • Charge Converters: Handles conversions for electrical charge, including: • Linear Charge Density • Surface Charge Density • Volume Charge Density • Linear Current Density • Surface Current Density • Power Converter App works with both iPhones, iPads and Mac Multiple Unit Compatibility: Supports a wide range of units for all electrical parameters, including Ohms, kiloOhms, Farads, Henrys, kVA, Volts, Weber, and more.

About

DC Wire Sizer

Calculate appropriate DC wire sizes for electrical projects, preventing equipment damage and fires. Save, edit, and export wire run details for electrical plans and material purchases. Features a wizard for easy sizing for all users.

Highlights
  • Calculates wire size, voltage drop, and ampacity
  • Supports custom DC voltages up to 500 amps
  • Save, edit, and export wire run details
  • Sizer Wizard for easy calculations
  • Select marine standards (ABYC or ISO)
  • Choose from various wire types and insulation ratings
Features
Currently charting
Read full description

Adding accessories (bilge pumps, electronics, solar, etc.) or upgrading batteries (AGM, Li, etc.) this year?  The #1 Cause of Boat and RV fires is DC wiring!  Undersized wires can damage equipment or cause fires.  The top-rated DC Wire Sizer calculates wire size for any DC voltage (ideal for solar in series). Plus lets you SAVE, EDIT, SUM, EMAIL and EXPORT the wire runs and material for your electrical plan, wire purchases, work orders, and records. And the Sizer Wizard option makes wire sizing easy for EVERYONE! Fast and safe wire sizing calculator for your next DC wiring project (battery, charger, inverter, trolling motor, stereo, and more). Designed with and for Marine Electronics Installers, Repair Services, Boat Builders, Surveyors, Do-It-Yourselfers, and Boat Owners. ONLY DC WIRE SIZER OFFERS these FEATURES: - Select any DC voltage and up to 500 amps - Results display wire size, VOLTAGE DROP (VD), and AMPACITY! - More granular “What if” analysis of ampacity & VD based on wire sizes & length - Choose from three methods of entering wire lengths for fast entry including separate positive/negative wire lengths (when different or negative is contact grounded, like a starter) - SAVE Wire Runs with the option to select or enter Wire Run & Project Name, wire type, wire color, status, and material source (Inventory or Buy) - EDIT Wire Runs including wire length, amps/watts, max voltage drop, insulations, inside/outside engine room, bundle, and the fields above. - SUMs active wire run lengths by size, type, and color to make purchasing easier and less expensive when by the reel (25’, 50’, 100’, etc.) - Select from a wire type list (e.g., primary, battery, safety, flat, duplex, triplex, mast, twisted, bilge, trailer, and solar cable) - Select marine standards (ABYC or ISO) - Change Unit of Measurement (Feet or Meters) in existing Wire Runs - Easy to use Sizer Wizard - Email and Export of Wire Runs and Raw Material MORE FEATURES: - Set default Wire Gauge (AWG, SAE, or MM2) - Set default Unit of Measure (feet or meters) - Select or enter Maximum Voltage Drop % - Select Bundle Size (1, 2-3, 4-6, 7-24, and 25+) - Select Insulation rating (60°, 75°, 80°, 90°, 105°, 125°, and 200°C) - Tap Inside/Outside Engine Room - Spin Amp/Watts and Wire Length for fast entry - Built-in Help and Technical Reference includes installation tips, connector types, color codes, tables (Voltage Drop, Ampacity, & Bundle), formulas (Power Triangle, Ohm's Law, etc.), recommended tools/books, and more. HERE’S WHAT REVIEWERS ARE SAYING: "The DC Wire Sizer is the most complete and comprehensive marine DC wire-sizing tool available. Developed for both marine professionals (the Wire Sizer Pro) and the occasional tinkerer (the Wire Sizer Wizard), the app determines the proper wire size, along with the voltage drop and ampacity by using the ABYC E-11 or ISO 10133 formulas and tables.” -  OnboardOnline (2013) "Stay organized by adding a wire description to the wire run and assign it to a project name (ie boat name, owner or work order). Mark the wire run as "Complete" or “Cancelled”, re-order wire runs within a project or move them between projects. Tired of adding wire runs in order to figure out what to purchase and how much? DC Wire Sizer sums the active wire runs for you by wire size (e.g. 8 AWG) and type (e.g. Safety Duplex, Battery Cable, and Primary Wire).” - marinabusiness (AU 2013) "If you're doing a lot of wiring on your boat, the app allows you to save the calculations with project names and wire type.  The app then can sum the length of the wire runs by wire type and size which can be used as a shopping list for your projects.  No other app offers these unique features and that's what makes it a winner.”  - i-marineapps (2013) "This is the best wire sizer program I have seen to date.  I can size and make a list at the same time also there is a better selection of amps and volts.” - Keith Herridge, Special Projects, Lyman-Morse Boatbuilding

Screenshots

Ohms Law Calc.4 screens
DC Wire Sizer4 screens

Verdict

The call

The clearest difference is review sentiment: DC Wire Sizer at 100% against Ohms Law Calc.'s 50%. DC Wire Sizer also leads on in-app purchases (none vs 1) and ads (none vs shown). Ohms Law Calc.'s advantage is price (Free vs $2.99) and update cadence (every 2 months vs every 20 months). On device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Ohms Law Calc. is free to download; DC Wire Sizer costs $2.99 up front. Ohms Law Calc. sells 1 one-off in-app purchase. DC Wire Sizer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

DC Wire Sizer holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Ohms Law Calc. has 1.3K ratings behind it against 24, so its average is the more settled of the two. Written reviews point the same way: 50% of Ohms Law Calc.'s written reviews are positive against 100% of DC Wire Sizer's.

UpkeepUpdate frequency

Ohms Law Calc. ships an update every 2 months, DC Wire Sizer every 20 months. The most recent releases landed on October 14, 2026 and October 3, 2026 respectively.

Scorecard10 real differences · 1 level
Ohms Law Calc. versus DC Wire Sizer: the parameters behind the verdict, then further details
ParameterOhms Law Calc.DC Wire Sizer
PriceFree — better$2.99
Rating4.7 (1.3K ratings)5.0 (24 ratings) — better
Positive reviews50.0% of reviews100.0% of reviews — better
Number of ratings1.3K — better24
Update frequencyEvery 2 months — betterEvery 20 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
Best chart rank—#169 — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.69.0 — better
Further details — not scored
Size59 MB21 MB
Age rating4+4+
DeveloperV PUGAZHENTHIDirty Dog Software, LLC

Customer experience

Ohms Law Calc.

All ratings1,326 ratings
Positive92.8%
Neutral3.5%
Negative3.7%
Written reviews44 reviews
Positive50.0%
Neutral6.8%
Negative43.2%

DC Wire Sizer

All ratings24 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews14 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Ohms Law Calc.

Reported bugs

3 issues
  • Paid version not unlocking
  • Repeatedly prompting for payment after already paid
  • Keyboard overlaying results making it difficult to see

Requested features

3 requests
  • Add more electrical conversions and calculations
  • Add ability to input voltage and resistance to get amps and watts
  • Add kVA, rms, and other popular needed conversions

DC Wire Sizer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Ohms Law Calc.

One-time1
  • Ohms Law Calc.$3.99
None

DC Wire Sizer

No in-app purchases

Questions

Is Ohms Law Calc. free?
Ohms Law Calc. is free to download, with in-app purchases available.
Is DC Wire Sizer free?
DC Wire Sizer costs $2.99, with no in-app purchases.
Which has better reviews, Ohms Law Calc. or DC Wire Sizer?
DC Wire Sizer is rated higher. Ohms Law Calc. averages 4.7 out of 5 from 1.3K ratings, while DC Wire Sizer averages 5.0 from 24 ratings.
Do Ohms Law Calc. or DC Wire Sizer have ads?
Ohms Law Calc. shows ads; DC Wire Sizer does not.
Which is updated more often, Ohms Law Calc. or DC Wire Sizer?
Ohms Law Calc. ships an update every 2 months, and DC Wire Sizer every 20 months. Most recently, Ohms Law Calc. was updated on October 14, 2026 and DC Wire Sizer on October 3, 2026.

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