Comparison

DC Wire Sizer vs Voltage Drop Calculator.

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

Head to head
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

About

Voltage Drop Calculator.

Calculate voltage drop and wire size using both NEC and IEC standards. Supports various load types, conductor materials, and system configurations. Generates detailed reports for electricians, engineers, and contractors.

Highlights
  • NEC and IEC dual standards
  • Voltage drop and wire sizing calculations
  • Support for continuous load and corrections
  • Copper or Aluminum conductor options
  • Single-phase and three-phase systems
  • Automatic compliance checks
  • PDF report generation
Features
Read full description

Perform accurate Voltage Drop and Wire Sizing calculations for both NEC® (National Electrical Code) and IEC standards. Built for electricians, engineers, and contractors who need reliable results on the go. Voltage Drop Calculator • Dual standards: Switch between NEC (AWG/Imperial) and IEC (mm²/Metric) • Enter voltage, current, run length, and power factor • Supports continuous load (125%), grouping, and ambient temperature corrections • Copper or Aluminum conductors for single-phase and three-phase systems • Detailed results including ampacity, derating, voltage drop, and load voltage • Automatic compliance checks (e.g., ≤ 3% for branch circuits) Wire Size Calculator (Reverse) • Calculates required wire size for a target voltage drop % • Suggests optimal AWG, kcmil, or mm² • Uses NEC Chapter 9, Table 9 (AC impedance) with DC fallback Professional Tools • Wire converter (AWG/kcmil ↔ mm²) • Generate and share PDF reports • Handy electrical formula cards • Localized in English, Spanish, French, German, Italian, Dutch, Portuguese, and Chinese

Screenshots

DC Wire Sizer4 screens
Voltage Drop Calculator.4 screens

Verdict

The call

The clearest difference is review sentiment: DC Wire Sizer at 100% against Voltage Drop Calculator.'s 33%. DC Wire Sizer also leads on in-app purchases (none vs 1) and ads (none vs shown). Voltage Drop Calculator.'s advantage is price (Free vs $2.99) and update cadence (every 3 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

Voltage Drop Calculator. is free to download; DC Wire Sizer costs $2.99 up front. Voltage Drop Calculator. 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 4.6. That said, the two scores are not equally well evidenced: Voltage Drop Calculator. has 410 ratings behind it against 23, so its average is the more settled of the two. Written reviews point the same way: 100% of DC Wire Sizer's written reviews are positive against 33% of Voltage Drop Calculator.'s.

UpkeepUpdate frequency

DC Wire Sizer ships an update every 20 months, Voltage Drop Calculator. every 3 months. The most recent releases landed on August 24, 2026 and September 18, 2026 respectively.

Scorecard10 real differences · 1 level
DC Wire Sizer versus Voltage Drop Calculator.: the parameters behind the verdict, then further details
ParameterDC Wire SizerVoltage Drop Calculator.
Price$2.99Free — better
Rating5.0 (23 ratings) — better4.6 (410 ratings)
Positive reviews100.0% of reviews — better33.3% of reviews
Number of ratings23410 — better
Update frequencyEvery 20 monthsEvery 3 months — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
Best chart rank#194 — better—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS9.0 — better17.6
Further details — not scored
Size21 MB51 MB
Age rating4+4+
DeveloperDirty Dog Software, LLCV PUGAZHENTHI

Customer experience

DC Wire Sizer

All ratings23 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews14 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Voltage Drop Calculator.

All ratings410 ratings
Positive90.2%
Neutral4.1%
Negative5.6%
Written reviews12 reviews
Positive33.3%
Neutral8.3%
Negative58.3%

In-app purchases

None

DC Wire Sizer

No in-app purchases

1 purchases

Voltage Drop Calculator.

One-time1
  • Go Pro$4.99

Questions

Is DC Wire Sizer free?
DC Wire Sizer costs $2.99, with no in-app purchases.
Is Voltage Drop Calculator. free?
Voltage Drop Calculator. is free to download, with in-app purchases available.
Which has better reviews, DC Wire Sizer or Voltage Drop Calculator.?
DC Wire Sizer is rated higher. DC Wire Sizer averages 5.0 out of 5 from 23 ratings, while Voltage Drop Calculator. averages 4.6 from 410 ratings.
Do DC Wire Sizer or Voltage Drop Calculator. have ads?
Voltage Drop Calculator. shows ads; DC Wire Sizer does not.
Which is updated more often, DC Wire Sizer or Voltage Drop Calculator.?
DC Wire Sizer ships an update every 20 months, and Voltage Drop Calculator. every 3 months. Most recently, DC Wire Sizer was updated on August 24, 2026 and Voltage Drop Calculator. on September 18, 2026.

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