PRE-LAUNCH Launching on iOS & Android · July 2026 → Join the waitlist →
Launching · App Store + Google Play · July 2026

Four trades. Built for the field.

CalcRig is the calculator built for the back of the truck — concrete, BTU, wire size, fixture units. Code-cited, offline-first, no ads. Stop doing trade math on scrap paper.

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✓ 16+ calculators ✓ 4 code sets — NEC, ASHRAE, UPC, IRC ✓ 100% offline ✓ No ads, no tracking
CalcRig — Electrical trade, Wire Size calculator: 5 A amperage returning 14 AWG with 15 A ampacity, 3.14 Ω/1000 ft, NEC 310.16 cited
Wire size · 60 A 6 AWG NEC 310.16
No signal · still works
Offline-first
Concrete · slab 20.1YD³ 12.5m × 8.2m × 0.15m
Scroll
NEC 310.16Wire ampacity✦
ASHRAE 62.1Ventilation✦
UPC Table 6-3Fixture units✦
IRC R301Climate zones✦
Manual JHeat load✦
NEC Ch. 9Conduit fill✦
NEC Art. 220Panel load✦
ACI 318Concrete✦
The problem

Trade math on scrap paper costs you money.

The notebook in your truck doesn't cite NEC. The calculator on your phone doesn't know what a board foot is. Spreadsheets don't open in a basement.

Truck cab · 7:42 am
12.5 × 8.2 × 0.15 =
15.36 m³ ??
+ 10% waste = ~17?
order 18 yds
RECONVERT TO YD³
~20-21 yd³ order what?
Notebook · pencil2nd truck trip
Service van · basement
Phone calc:
60 ÷ ?? = ___
8 AWG undersized
10 AWG too small
need NEC chart
no signal · book in van
→ drive back ↩
Generic calculator+45 min
CalcRig · 1 tap

One thumb. Right answer. Code attached.

Concrete · slab 20.1YD³
Wire · 60 A · 75°C 6 AWGCu
Voltage drop · 80 ft 2.1%OK
NEC 310.16 citedoffline · no ads
What's in the rig

Four trades. Sixteen calculators. Zero generic math.

Tap a trade to see what's inside.

01 · Construction

Pour the slab,
not the math.

Concrete volume, lumber board feet, stud count, drywall sheets, roofing squares, paint coverage — every formula a foreman reaches for, on one screen.

  • ✓Concrete volumeCubic yards or m³ for footings, slabs, walls, columns. L × W × D
  • ✓Lumber & board feetBoard feet from dimensions. Stud count for any wall length and OC spacing.
  • ✓Drywall, roofing, paintSheets needed, roofing squares, paint coverage by gallon — waste factor included.
CalcRig Construction: Concrete Volume showing 12.5×8.2×0.15 inputs and 20.1 YD³ result with ACI 318 citation
Slab pour · 1 tap 20.1YD³ 12.5m × 8.2m × 0.15m
Order on the truck +10%waste 22 YD³ delivered
02 · HVAC

Sized right.
First time.

BTU load, duct sizing, refrigerant charge, air changes per hour. Hand a homeowner numbers, not vibes.

  • ✓BTU loadHeating & cooling load by climate zone, insulation, square footage.
  • ✓Duct sizingRound & rectangular dimensions for target CFM and friction rate.
  • ✓Refrigerant & ACHSubcooling and superheat calcs. Air changes per hour for any room. ASHRAE 62.1
CalcRig HVAC: BTU Load with length/width/ceiling inputs, Average insulation, climate Zone 4 — Mixed
Manual J · zone 4 24,800BTU 62 m² · avg insul.
Air changes 5.2ACH ASHRAE 62.1
03 · Electrical

Code-cited
amperage.

Wire gauge, voltage drop, conduit fill, panel load. Every result tagged with its NEC article — inspector ready.

  • ✓Wire gauge & voltage dropSizing for any amperage and run length. NEC 310.16
  • ✓Conduit fillEMT, IMC, RMC, ENT — all wire combinations. NEC Chapter 9
  • ✓Panel loadConnected and demand loads, balanced across phases. NEC Article 220
CalcRig Electrical: Wire Size for 5 A amperage, returning 14 AWG with 15 A ampacity, 3.14 Ω/1000 ft, NEC 310.16 cited
5 A · copper 14 AWG NEC 310.16
Ampacity rating 15A 75°C · Cu
04 · Plumbing

Fixture units,
fixed.

Pipe sizing, flow rate, drainage slope, water heater sizing, fixture-unit reference. Without the table on your truck dash.

  • ✓Pipe sizing & flowDiameter, flow, velocity for water supply, drainage, gas piping.
  • ✓Fixture unitsWSFU and DFU per IPC and UPC. UPC Table 6-3
  • ✓Slope & water heaterDrain slope, fall-per-foot. WH sizing by occupancy.
CalcRig Plumbing: Pipe Sizing with fixture-unit picker rows (Lavatory, Shower, Bathtub, Toilet, Kitchen Sink, Dishwasher, Washer, Hose Bib), total 23 WSFU
Fixture units 23WSFU UPC Table 6-3
Per fixture 8types supply pipe
How CalcRig thinks

Try it

A real calculator. Right here.

Pick a job — see CalcRig solve it with the formula and code reference attached.

Pick a job.
See the math.

This is the same calculator that ships on iOS and Android. Tap a scenario and watch the result animate in.

01
Slab pour · garage floor
12.5m × 8.2m × 0.15m
ACI 318
02
Footing · perimeter
28m × 0.6m × 0.45m
ACI 318
03
Patio · backyard
5.5m × 4.0m × 0.10m
ACI 318
04
Driveway · 2 cars
18m × 6m × 0.12m
ACI 318
Concrete
01 · Construction
Metric · YD³ out
12.5m
8.2m
0.15m
Concrete needed
Volume 20.1YD³
+10% waste factor 22.1YD³
Order qty (rounded) 23YD³
12.5 × 8.2 × 0.15 × 1.30795 ACI 318
Built for the field

Designed for gloves, sun, and zero signal.

The opinions baked into every screen — built by tradespeople who got tired of opening three apps to size a feeder.

Code-cited

Every result ships with the
code reference attached.

NEC 310.16 next to every wire size. ASHRAE 62.1 next to every ACH. Hand the inspector your phone, not a wink.

NEC 310.16ASHRAE 62.1UPC Table 6-3IRC R301NEC Ch. 9
Imperial ↔ Metric

One tap. Inches to mm,
BTU to kW, gallons to litres.

Set it once in Settings. Every calculator, every result switches. No conversion factor on a Post-it.

1¼"→32mm
ImperialMetric
Offline-first

No signal? No problem.

Every calc runs on-device. Basements, tunnels, rural service — everything works.

No bars App: ✓ ready
Glove-friendly

Big targets. High contrast.
Outdoor mode.

56pt minimum tap targets — well above Apple's 44pt floor. Auto-bumps contrast in direct sun.

Tap target 56 × 56 pt
Save & share

Export as PDF or text.
Share to anything.

Every calculation's history is one tap. Send via Messages, email, AirDrop, anywhere.

slab-pour-may.pdfPDF
wire-feeder-svc.txtTXT
Local-first

Your data stays on your device.
No accounts. No tracking. No ads. Ever.

CalcRig stores everything locally. No server. No analytics. Use it anonymously, or sign in with Apple if you want a backup.

No trackingNo adsNo data soldLocal-onlySign in with Apple · optional
Memory

Inputs remember
between sessions.

Open the slab calc tomorrow — yesterday's dimensions are still there. Pick up where you left off.

Last saved 12.5 × 8.2 × 0.15
0+
Specialized calculators across 4 trades
0
Code sets — NEC, ASHRAE, UPC, IRC
0%
Of calculators run offline
0
Ads, tracking, or data sold to third parties
Pricing

All calculators are free. Pro adds the pro tools.

Every calculator works free, forever. Pro unlocks cloud sync, PDF export, unlimited history, and project grouping.

Free
$0forever
The full calculator suite. No account, no credit card, no demo limits.
  • All 16+ calculators
  • NEC, ASHRAE, UPC, IRC references
  • Imperial ↔ Metric toggle
  • Last 30 calculations saved locally
  • Text share
  • Offline-first, no ads
Get the free app
No purchase required
Monthly
$2.99/ month
Pro features, billed monthly. Cancel anytime in App Store / Play settings.
  • Everything in Free
  • Unlimited calculation history
  • Cloud backup & cross-device sync
  • PDF export & share
  • Project grouping
  • Priority support
Subscribe monthly
In-App Purchase · auto-renew
Best value
Yearly
$19.99/ year
Save 44% vs. monthly · $1.66/mo
For pros who'll use CalcRig every week. Same features, half the price.
  • Everything in Monthly
  • Save 44% vs. monthly billing
  • Annual code-table updates
  • New calculators included
  • Migrate to Lifetime anytime
Save 44% — yearly
In-App Purchase · auto-renew
Lifetime
$49.99once · forever
Best for long-term · pays back in ~2.5 yrs
Pay once, own it forever. Every future calculator and code update included.
  • Everything in Yearly
  • One-time payment, no renewals
  • All future trades included
  • Restore on any device
  • Founder badge in app
Buy lifetime · $49.99
In-App Purchase · one-time

All prices in USD · Billed by Apple App Store / Google Play · Cancel anytime in your store settings

Questions

Everything you'd ask a buddy.

CalcRig launches on the App Store and Google Play in July 2026. Join the waitlist below — you'll get an email the day it goes live.
Yes — every calculator runs 100% on-device. No cell signal, no Wi-Fi, no problem. We don't make a server call to compute a wire size. Your inputs and history stay on your phone.
CalcRig references NEC (electrical), ASHRAE (HVAC), UPC and IRC (plumbing), and IRC (construction). The exact code reference shows up next to every result so you can verify it against the book.
All payments go through your App Store or Google Play account — never through us. Subscriptions auto-renew per Apple/Google's standard terms; cancel any time in your store settings. The Lifetime tier is a single one-time purchase.
No. CalcRig works fully anonymously — open it and start calculating. If you want to back up your history or sync across devices, you can sign in with Apple. We don't collect emails, contacts, or tracking data.
Never. CalcRig stores everything locally on your device. We don't run analytics, we don't sell data, we don't show ads. Notchip (the company behind CalcRig) makes money from app purchases — that's it.
Both. Native iOS and Android, launching simultaneously in July 2026. iPad-optimized too.
Pre-launch · July 2026

Be first on the rig.

Drop your email — we'll ping you the second CalcRig hits the App Store.

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