DC Wire Sizer is the most complete and comprehensive marine DC wire sizing tool in the App Store. Designed for both the marine professional (Sizer Pro) and the occasional user (Sizer Wizard, with just 4 easy questions). DC Wire Sizer is an indispensable app for anyone adding, upgrading or inspecting marine DC wiring.


"So great to see such a simple user friendly App. That virtually anyone can use with speed and accuracy. No more pulling out the marine catalog and trying to find the wire sizing charts and the calculator. Talk about a time saver!! Five Stars Guys!”

"The App is VERY user friendly -- almost scary good."

"I think this is an incredible app. I wish I had access to it when I rewired my boat. As it is, I think I over-wired some things and under-wired others. I still have some wiring to complete and having access to this app will greatly simplify my calculations."

All too often boat wire is either oversized, costing you more money, or worse, the wire is undersized potentially causing damage to motors and electronics and wasting energy. There is also an increased risk of a failed survey or fire. The #1 cause of boat fires is DC shorts/wiring! Don’t let this happen to you.

Both the Sizer Pro and the Sizer Wizard determine the proper wire size along with the voltage drop (VD) and ampacity using the ABYC E-11 or ISO 10133 formulas and tables.

SIZER PRO -- is designed for marine professionals, tailored for speed with advanced options, such as 7 insulation ratings, 5 wire bundle sizes and maximum VD percent. For more granular analysis of VD and ampacity, tap the results and adjust the wire size or length.

SIZER WIZARD -- is perfect for the occasional user, stepping effortlessly though 4 easy questions, before displaying the results. In each step, the user finds information, tips and help text instantly accessible.

SAVED WIRE RUNS -- can be assigned a description within a Project (e.g. boat or job name); a wire type; wire colors; a status (Active, Completed, Cancelled), material sources (Use Inventory or Buy) and more. And you can edit, email or export the wire run from the Wire Run or Raw Material List.

THE WIRE RUN LIST -- no need to write down all of the wire run information (e.g. wire size, length, wire type, color, name, and more). Saved wire runs can be viewed, marked or filtered (Active, Completed, Cancelled); or Re-order wire runs within, or between, projects in the Wire Run list.

THE RAW MATERIAL LIST -- tired of making multiple trips to the marine store because you forgot to add in a wire run and can't remember whether it was 8 AWG or 10 AWG? DC Wire Sizer sums active wire runs for you by wire size (e.g. 8 AWG) and type (e.g. Safety Duplex, Primary, etc.). Mark or filter your wire by "Use Inventory" or "Buy”.


- Two calculator interfaces to choose from -- Pro and Wizard
- Save your Wire Runs -- edit, email or export them any time
- Add a wire description and assign it to a project
- Select wire type, wire color, status (Active, Complete or Cancelled) and material source (Buy or Use Inventory)
- Three methods of measuring (One-Way, Round Trip or individual positive and negative)
- Select maximum voltage drop %, bundle size and insulation rating
- Select a fractional amp, watts or enter a fractional volt for low voltage projects
- Select or enter any voltage and up to 500 amps for solar and wind applications
- Sum the wires by gauge and type for checking inventory or purchasing

- Email and Export Wire Runs and Raw Material Lists
- Choose your Settings:
--Marine Standard; ABYC E-11 or ISO 10133
--Wire Gauge (AWG, SAE, or MM2)
--Unit of measure (feet or meters)
- Built-in Help text for each screen and field

- Built-in Technical Notes has installation tips, wire colors, connector types, formulas (ABYC, ISO, Power Triangle, Ohm's Law, etc.), recommended tools, and more.

Dirty Dog Software, LLC, solar powered iOS software development.

What’s New

Version 1.1.1

- Resolved issue accessing Settings on iPad (only iPads using version 1.1 were affected).
- Added the ability to change the units of measure (aka feet or meters) on existing wire runs.
- Added Solar PV Cable to the list of wire types.

Ratings and Reviews

5.0 out of 5
8 Ratings
8 Ratings
HR Rasmus Hull 186 ,

Awesome for pros and those of us with no experience!

Time to rewire the 40 year old, but good, sailboat. No other app or book out there is making this task so doable and easy! I can enter the data for my husband as he crawls around in small spotsbin crazy places. This wire sizer app will probably save our marriage--no more digging through Nigel, codes, calculating and arguing! Easy enough for me to use, and the "Captain" can walk into a shop and discuss what he needs and how much he needs with confidence with a "pro." Actually, he now thinks he knows more than the pros. I won't burst his bubble that it's the wire sizer that has made him feel so smart :-)

Gail from cape cod ,

Do it yourselfer

This app is easy to use and understand. The step by step instructions filled in any gaps for me. It's worth the money ten times over!

RJRey ,

No Experience Necessary

I know NOTHING about wiring a boat and yet, I was able to use this app to determine what I needed. Easy to use and very helpful.


Gayle Dunham
19.3 MB

Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© 2018 Dirty Dog Software, LLC


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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