Nullfield Calculator
Misclose
Bearing Distance
Bearing Distance

How to Use

Enter bearings using the format D.MS (e.g. 42°01'36" as 42.0136).

Distances should be in metres.

Optionally, you can enter a bearing delta (Δ) in the input above the add bar. This value will be added to every new leg's bearing before it is stored. Useful for applying a constant offset to all bearings.

You can do basic arithmetic in the distance field, along with these special functions:

  • sin(x)
  • cos(x)
  • tan(x)
  • asin(x)
  • acos(x)
  • atan(x)
  • sqrt(x)
  • pow(x, y)
  • pi
  • e

You can also use the following units:

  • in – Inch = 0.0254
  • ft – Feet = 0.3048
  • yd – Yard = 0.9144
  • li – Link = 0.201168
  • ch – Chain = 20.1168

For example, you could enter 100li + 2ch to get 60.350m.

You may enter distances at any precision; they will be displayed to 3 decimal places in the table.

Calculation Details

The app calculates the misclose (closure error) using the following steps:

  • Bearings and distances are interpreted as vectors (legs) radiating from a common origin.
  • Each leg is converted to Cartesian (x, y) coordinates using its bearing and distance.
  • The endpoint of each leg is computed by summing the vectors sequentially.
  • The misclose is the vector from the final endpoint back to the starting point.
  • The misclose's distance is the closure error, and its bearing is the direction of the error.
  • The reverse is the bearing in the opposite direction (misclose + 180°).

This method is standard in surveying and traverse adjustment. The app does not apply any correction or adjustment—just a direct vector sum and closure calculation.

App Features

  • Add Legs: Enter a bearing and distance, then click Add to add a new leg to the table. (If a bearing delta is set, it will be added to the input bearing.)
  • Edit/Remove Legs: Use the row menu (more_vert) to add above/below or delete a leg. Reverse a leg's bearing with the swap_horiz button.
  • Reorder Legs: Drag the drag_indicator icon to reorder legs by drag-and-drop.
  • History: Click the history button in the top bar to view and restore previous calculations.
  • Map View: Click the map button in the top bar to visualize the legs and misclose on a map.
  • Misclose Calculation: The result panel always shows the current misclose bearing, reverse, and distance.

All changes are saved automatically. The app is designed for mobile and desktop use.

PWA & Installation

This app is a Progressive Web App (PWA). You can install it to your device for a native-like experience, with offline support and automatic updates.

  • Offline Support: The app works offline after your first visit. You can use all features without an internet connection.
  • Home Screen Install: Add the app to your home screen for quick access, just like a native app.
  • Automatic Updates: The app will update itself in the background when new features or fixes are released.

How to Install:

  • Android/Chrome: Tap the browser menu (⋮) and select Add to Home screen.
  • iOS/Safari: Tap the ios_share share icon, then choose Add to Home Screen.
  • Desktop: In Chrome/Edge, click the install icon in the address bar or use the browser menu to install the app.

If you experience issues with updates, try refreshing the app or reinstalling from your browser.
Bearing Distance
Enter at least 2 legs