# COGO: Land Survey Calculator — Traverse Closure, Area & CAD

> Offline land surveying calculator for traverse, area, curves, and CAD export. (iPhone/iPad app by Gabriel John Fordan.)

- Source: https://appshunter.io/ios/app/cogo-land-survey-calculator/id6777398516 (this page in markdown: same URL + `.md`)
- Developer: [Gabriel John Fordan](https://appshunter.io/developer/6777398518)
- Category: Productivity, Utilities
- Price: Free with in-app purchases
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 26.0 · 10 MB
- Languages: American English, European Spanish
- Released: 2026-06-10
- Data updated: 2026-10-31
- Monetization: free with in-app purchases

## What is COGO?

Offline COGO for land surveyors: traverse, closure, curves and CAD export. New Home Screen widgets and calculator search.

WHAT YOU CAN DO
• Bearing-and-distance traverse with running coordinates; edit any leg in place; enter legs in metres, feet, US survey feet, or links
• Inverse / join: two points to distance, azimuth, and quadrant bearing
• Inverse list / radiations: bearing & distance from one point to every other point
• Sideshot reduction: horizontal angle, zenith, and slope distance to northing, easting, and elevation
• Closure: linear misclosure, misclosure bearing as azimuth or quadrant (your choice), precision ratio (1 : N)
• Balance a traverse by the Compass (Bowditch) or Transit rule
• Closed traverse from field angles — angular misclosure and angle balancing
• Enclosed area by coordinates, with acres / hectares and perimeter
• Horizontal curve solver — R, Δ, arc, tangent, chord, external, mid-ordinate, degree of curve, PC & PT — plus a stakeout table
• 3-point circle / arc — fit a circle through three points and divide the arc into stake points
• Angle calculator — add/subtract angles, angle between bearings, bearing ± angle
• POB calculator — chain editable bearing-distance calls from a point of beginning
• Intersections — bearing-bearing, bearing-distance, distance-distance — and 3-point resection
• Line tools — four-point intersection, parallel and perpendicular lines
• Common tangent — all four tangents between two circles, with offsets
• Two unknowns — solve two missing traverse distances, bearings, or one of each, offsets included
• Recessed invert — slant tape shot to invert depth and elevation
• Unit converter — chains, links, feet & inches, varas, metres, acres, hectares, gons: type once, see every unit
• UTM converter — latitude/longitude as decimal degrees, DMS with N/S/E/W, DDMMSS, or packed D.MS
• State Plane (SPCS83 and SPCS2022 preview) — lat/lon to grid with scale factor, convergence, and combined factor
• Grid ↔ Ground converter — distances through a typed or zone-derived combined scale factor
• Horizontal alignment — PI-chained tangents, curves, optional spirals, stationing, station & offset, stakeout
• Predetermined / hinged area subdivision — parallel cutoff or hinged line to a target area
• Metes-and-bounds legal description — generate a written deed description from a closed traverse
• Plot / sketch view of the traverse with north arrow, scale bar, and legend
• Import/export points as CSV in your column layout (PNEZD, PENZD, NEZ, ENZ …) and delimiter
• Export DXF (AutoCAD R12) and a one-page PDF report — CSV, DXF, and PDF export are free
• Work in DMS, decimal, or packed D.MS; azimuth or quadrant; feet or metres — set your defaults once
• Native iOS keyboard or the in-app survey keypad with DMS keys
• Ask “Theo,” the on-device AI assistant (Apple Intelligence), in plain English

PRIVATE BY DESIGN
100% offline. No account, no network, no ads, no tracking. Your jobs and points never leave your device.

WHO IT'S FOR
Land surveyors, party chiefs, survey techs, civil engineers, and students.

FREE & PRO
Free includes one job and up to ten points, full on-screen computation, and CSV / DXF / PDF export. COGO Pro unlocks unlimited jobs and points, Compass/Transit closure adjustment, and enclosed-area output — as a Weekly, Monthly, or Yearly subscription, or a one-time Lifetime purchase.

Always verify computed results against your project control. This app is a field calculator, not a substitute for a licensed surveyor's checks.

SUBSCRIPTION DETAILS
COGO Pro Weekly, Monthly, and Yearly are auto-renewable subscriptions; Lifetime is a one-time purchase. Payment is charged to your Apple Account at confirmation. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period; manage or cancel anytime in Settings.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://cogo.vendrato.com/privacy

## Key features

- Bearing-and-distance traverse with running coordinates
- Closure calculations and balancing
- Enclosed area and perimeter calculation
- Horizontal curve solver and stakeout table
- CAD export (DXF) and PDF report
- Unit and coordinate system conversion
- On-device AI assistant

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| COGO Pro Monthly | $4.99 | per month |
| COGO Pro Yearly | $39.99 | per year |
| COGO Pro Weekly | $2.99 | per 7 days |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| COGO Pro Lifetime | $99.99 | one-time |


## Is COGO safe?

Not enough ratings yet to assess COGO.

## Is COGO legit?

COGO: Land Survey Calculator appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for COGO is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Frequently asked questions about COGO

### What can COGO calculate?

COGO can calculate traverse closure, enclosed area, horizontal curves, and perform various geometric intersections. It also includes unit and coordinate system converters, and can generate metes-and-bounds descriptions.

### Does COGO work offline?

Yes, COGO is designed for 100% offline use. Your job data and points remain on your device, ensuring privacy and accessibility without a network connection.

### What export formats does COGO support?

COGO supports exporting data as CSV, DXF (AutoCAD R12 compatible), and a one-page PDF report. These export options are available for free.

### What units can I use with COGO?

You can enter and work with legs in meters, feet, US survey feet, or links. The unit converter also supports acres, hectares, varas, and gons.

### How does COGO handle coordinate systems?

COGO supports UTM conversion and State Plane (SPCS83 and SPCS2022 preview). It can convert between latitude/longitude and grid coordinates, including scale factors and convergence.

### What are the subscription options for COGO Pro?

COGO Pro offers weekly, monthly, and yearly subscription plans. These are priced at $2.99/week, $4.99/month, and $39.99/year respectively.

### Does COGO have ads?

No, COGO is designed to be ad-free. The app emphasizes privacy and does not contain advertisements or tracking.

### What is the AI assistant in COGO?

COGO includes an on-device AI assistant named 'Theo' (leveraging Apple Intelligence). You can ask it questions in plain English to help with calculations or app usage.

## Version history (last 5 releases)

### 2.8 — 2026-10-31

• Survey Quick Tools widget: open Unit Converter, Grade & Slope, Angle Calculator and Curve Solver from your Home Screen.
• Field Reference widget: common length and area conversions at a glance, with one-tap access to Unit Converter.
• Search calculators by name or description on iPhone and iPad.
• Widgets and search support English and Spanish.

### 2.7 — 2026-10-16

v2.7 adds a Unit Converter, built from a surveyor's request: "In our office we are constantly jumping between units."

• Type a length, area, or angle once and see it in every other unit at the same time: metres, international and US survey feet, feet and inches to 1/64", chains, links, rods, varas, yards, miles; square metres, hectares, acres, square chains; DMS, decimal degrees, gons, radians, and mils.
• Feet and inches type the way you write them: 12' 6 3/8", 12 6 3/8, or 12-6 3/8.
• A Foot Basis switch picks the international foot or the US survey foot for old records.
• Tap a row to copy it; touch and hold to convert from that unit.
• iPhone Duo: unfolded, it gets the iPad layout with the job sidebar and side-by-side traverse.

Find it under Calculators › Conversions. Fully offline. Thanks for using COGO Survey Calculator.

### 2.6 — 2026-10-13

Minor improvements. No changes to calculations, features, or your data.

Fully offline. Thanks for using COGO Survey Calculator.

### 2.5 — 2026-10-13

COGO now speaks Spanish.

• Every screen, calculator, Help & Guide page, the glossary and the PDF report are translated, with the field terms surveyors use: poligonal, rumbo, azimut, cierre, replanteo.
• COGO follows your device language. To use Spanish for COGO only, open Settings › Apps › COGO Survey › Language.
• Theo, the on-device assistant, answers in the language you ask in.
• CSV and DXF exports and the metes-and-bounds legal description stay in English, so files and deeds read the same for everyone.

Fully offline. Thanks for using COGO Survey Calculator.

### 2.4 — 2026-10-11

v2.4 adds an iPad redesign, a closed-traverse angle tool and a level-book misclosure check, and fixes the sample job, resection, State Plane feet, typed DMS and UTM.

• iPad redesign: a job sidebar, a traverse screen with entry form, legs and live plot side by side, large tool sheets, and tile grids for Calculators and Help.
• iPad shortcuts: ⌘N new job, ⌘↩ add leg, ⌘1/⌘2/⌘3 Traverse/Points/Plot, ⌘R Closure & Area, ⌘K Calculators. Return and Esc close sheets.
• Closed Traverse (Angles) works a closed loop from measured angles: misclosure check, allowable PASS or FAIL, angle balancing, azimuths, 1 : N closure, and Compass-adjusted coordinates. Save it as a job.
• Curve Solver takes a PI station and places the PC and PT from it.
• Level Book checks misclosure against C = k·√K, with FGCS loop presets or your own k. PASS or FAIL shows on screen and in the CSV.
• Sideshots can take a curvature & refraction correction, off by default. Grid ↔ Ground accepts orthometric heights (H + geoid N gives h).
• Resection takes clockwise angles at the station, works inside or outside the control triangle, and flags the danger circle and weak geometry.
• State Plane grid units default to the zone's legislated foot, and reset when you change zone.
• Typed DMS is strict: minutes and seconds must be under 60. Invalid entries show as invalid, not 0.

Fixed: the sample job drew every leg from point A since 2.3; it now closes at 1 : 12,116, and an earlier sample can be deleted and loaded again. Two-angle resection could return the wrong station; State Plane default feet were wrong in seven states; typed DMS dropped fractional minutes and lost a minus sign; a −0° latitude or longitude lost its sign; the level book's adjusted HI was off; long clothoid spirals were slightly inaccurate.

Fully offline. Thanks for using COGO Survey Calculator.

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All apps by Gabriel John Fordan: https://appshunter.io/developer/6777398518

## Related topics

[land survey calculator](https://appshunter.io/ios/topics/land-survey-calculator) · [cogo surveying](https://appshunter.io/ios/topics/cogo-surveying) · [cogo](https://appshunter.io/ios/topics/cogo)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-31.*