A web-based tool for solving multi-cache geocache coordinates using formulas. Perfect for multi-caches that require you to calculate waypoint coordinates based on information discovered at each stage.
The Multi-Cache Waypoint Solver helps geocachers solve multi-cache coordinates by allowing them to:
Enter the GC code (e.g., GC40). This will be used as the filename when saving. Required for browser storage.
Enter a descriptive name (e.g., "Mystery in the Forest"). This helps identify caches in your saved list.
Choose how you want to define your parameters:
Select from the dropdown to create sequential parameters. For example:
A-B = 2 parameters (A and B)A-E = 5 parameters (A, B, C, D, E)A-Z = 26 parameters (all letters)Enter any comma-separated letters to create custom parameter sets:
A,B,C,K,L,M,X,Y,Z - Skip letters as neededP,Q,R,S,T - Use only specific lettersA,C,E,G - Use non-sequential parametersEnter the total number of waypoints in the multi-cache (1-50). Each waypoint gets its own coordinate formula card.
Each parameter has two input fields:
The tool uses the standard geocaching coordinate format:
For example: N 50° 00.000 E 005° 00.000
Each coordinate digit field accepts either:
5 or 7You can use standard mathematical operations:
| Operation | Symbol | Example |
|---|---|---|
| Addition | + |
A+B |
| Subtraction | - |
A-B |
| Multiplication | * |
A*2 |
| Division | / |
B/2 |
| Parentheses | ( ) |
(A+B)*2 |
Downloads a JSON file to your computer. The filename will be based on the Geocache Code you entered (e.g., GC40.json).
Advantages:
Stores the formula in your browser's local storage for quick access.
Advantages:
See the Browser Storage section below for detailed information and constraints.
When saving, you can choose whether to include the parameter values (A, B, C, etc.):
Note: Comments are always saved regardless of this checkbox setting.
Browse your computer to select a previously saved JSON file.
Opens a modal showing all formulas saved in browser storage. Click any formula to load it, or click the Delete button to remove it.
Enter a direct URL to a JSON file hosted online. The formula will be fetched and loaded automatically.
Technical Details: The tool uses the browser's localStorage API to store formula data directly on your device. This is a key-value storage system built into modern web browsers.
When you click "Save to Browser", the following data is stored:
Each formula is stored with two localStorage keys:
gc_multi_[CacheCode] - Contains the full formula datagc_multi_list - Contains a list of all saved cache codesIf you save cache code GC40, it creates:
gc_multi_GC40 - The formula datagc_multi_list - Updated to include "GC40"Browser storage is NOT synced across devices or browsers.
Typical browser limits:
This is enough for hundreds of formulas, but very large multi-caches with many waypoints will use more space.
Your data can be lost if:
In private/incognito browsing:
You can inspect your browser's localStorage using browser developer tools:
gc_multi_To remove all saved formulas from browser storage:
You can create a link that automatically loads a formula when opened:
When someone clicks this link, the formula loads automatically!
Setup:
Waypoint 1: N 50° 0A.B00 E 005° 0C.D00
Waypoint 2: N 50° 0(A+1).E00 E 005° 0C.D50
Final: N 50° 0E.(A*100) E 005° 0D.(B+C)
As you progress: Fill in A at WP1, B at WP2, etc. Each coordinate updates automatically.
Cache uses: X, Y, Z parameters only
Setup: Use Custom List method: X,Y,Z
This creates only the three parameter inputs you need.
Fill in both the code AND the name fields. The name helps you remember which mystery this is when browsing your saved formulas.
Use the comment field under each parameter to note where the value came from (e.g., "Trees at WP1", "Year on memorial plaque").
Before heading out, verify your formulas produce reasonable coordinates (within expected geographic range).
You don't need all parameters at once! Enter formulas for all waypoints, then fill in parameter values as you discover them during the cache hunt.
Use "Save to File" to create backup copies of your formulas, especially for complex multi-caches. Browser storage is convenient but not permanent.
When sharing formulas for unsolved mysteries, uncheck "Save parameter values" to share the puzzle structure without spoiling the solution.
If a formula can't be evaluated (syntax error or missing parameters), it will show as ? in the result. Double-check your formula syntax and ensure all parameters are defined.
The red "Clear All" button resets the entire form to its default state. This includes:
A confirmation dialog appears to prevent accidental data loss.
All data is stored locally in your browser or in files you control:
Multi-Cache Waypoint Solver - A tool for geocachers by geocachers