# True-Wind Calculator — Sailing wind converter & log

> Calculates true wind speed and direction from vessel and apparent wind data. (iPhone/iPad app by Nejc Landeker.)

- Source: https://appshunter.io/ios/app/true-wind-calculator/id712909613 (this page in markdown: same URL + `.md`)
- Developer: [Nejc Landeker](https://appshunter.io/developer/712909616)
- Category: Navigation, Sports
- Price: Free with in-app purchases (on sale, was $1.99)
- Age rating: 4+
- Requires: iOS 16.0 · 1 MB
- Languages: American English, French (France), German (Germany), Italian, Slovenian
- Released: 2013-09-28
- Data updated: 2026-08-25
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/true-wind-calculator/id712909613/reviews.md

## What is True?

The wind you feel on a moving boat isn't the real wind. True-Wind Calculator turns the apparent wind you measure into the true wind you need — in two taps, no wind instruments required.

In use since 2013, completely rebuilt in 2026.

HOW IT WORKS
Enter boat speed, apparent wind speed, apparent wind angle and heading. The app does exact vector math — no lookup tables, no approximations — and gives you true wind speed and true wind direction instantly. Boat speed and heading can be filled automatically from GPS and compass with one tap.

FREE
• True wind speed, direction and angle — unlimited calculations
• One-tap GPS fill for boat speed and heading
• The formula explained, so you can trust the numbers
• Works completely offline — no account, no ads, no tracking

PRO (one-time purchase, no subscription)
• Performance — live VMG, target boat speed, % of target VMG and point of sail, driven by your boat's polar
• Tactics — tack preview, windward-mark laylines, and whether you can lay the mark
• Boat polars — pick a preset or build your own in the editor
• Compass rose view — heading, apparent and true wind on one dial
• Calculation history — every result logged with its inputs
• All speed units — knots, m/s, km/h, mph

Bought the app back when it was paid? Pro is already yours — it unlocks automatically.

PRIVACY
Everything stays on your device. Location is read only to fill the input fields and never leaves your phone. No analytics, no third-party SDKs.

## Key features

- True-wind calculation
- Vessel speed input
- Apparent wind speed input
- Apparent wind angle input
- Vessel heading input

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro Unlock | $4.99 | one-time |


## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/true-wind-calculator/id712909613/reviews.md

### 1/5 — Does not work for wind on port bow

*2022-08-26*

If you use relative wind of 180 or greater (ie on the port bow) the calculation seems to fail.

### 1/5 — Rubbish

*2021-12-06, version 2.1*

Calculations are false. The app is a fraud.

### 1/5 — Has flaws

*2018-11-28*

Does not calculate wind direction properly. Can be off as much as 200 degrees.

**Developer response:** Hi, have you checked the new version? It does much more. Hope it helps you.

### 1/5 — Don't waste u money

*2017-06-23, version 1.0*

It doesn't say you have to enter all the fields to then calculate the twd... hopeless

## Frequently asked questions about True

### What is True-Wind Calculator used for?

True-Wind Calculator helps you determine the true wind direction and speed. It uses your vessel's speed, the apparent wind speed and angle, and your vessel's heading as inputs.

### How much does True-Wind Calculator cost?

True-Wind Calculator is a paid app, available for $1.99. This one-time purchase grants you access to all its features.

### What devices is True-Wind Calculator available on?

True-Wind Calculator is compatible with iPhone, iPad, and iPod devices. It is designed for iOS users.

### When was True-Wind Calculator last updated?

The latest version of True-Wind Calculator, version 2.2, was released on November 3, 2022. This indicates regular updates to maintain functionality.

### What is the age rating for True-Wind Calculator?

True-Wind Calculator has an age rating of 4+. This means it is suitable for users of all ages, with no content restrictions.

### Does True-Wind Calculator have ads?

No, True-Wind Calculator does not contain advertisements. As a paid application, it offers an ad-free experience.

### Is True-Wind Calculator good for beginners?

While the app provides precise calculations, its utility is best for those familiar with sailing terminology and data inputs like vessel heading and apparent wind.

## Version history (last 5 releases)

### 3.1 — 2026-07-01

v3.1 — Pro performance tools for serious sailors.

• New: VMG and target boat speed, calculated against your polar curve (Pro)
• New: tack & layline tactics — know exactly when to tack and whether you can lay the mark (Pro)
• Pro remains a one-time unlock — no subscription, ever.

### 2.2 — 2022-11-03

- calculation formula redesign

### 2.1 — 2019-10-24

iOS 13 support
Bugfixes and improvments

### 2.0 — 2018-11-01

What's New:
- design update
- iPhone X support
- visual fixes

Oh, and an option to get current position and speed. Hope it helps.

### 1.0 — 2013-09-28

No release notes.

## Related topics

[apparent wind calculator](https://appshunter.io/ios/topics/apparent-wind-calculator) · [wind calculator](https://appshunter.io/ios/topics/wind-calculator)

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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 2026-08-25.*