Anchor Scope Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the water depth at high tide and your bow roller height.
- Set the scope ratio.
How it works
Rode = (depth + bow height) × scope ratio. 5:1 is typical for chain, 7:1+ for rope or rough weather.
Worked example
5 m depth, 1.5 m bow, 7:1. = 45.5 m of rode.
Common mistakes
- Using depth alone — add the bow height above the water.
- Forgetting to allow for the tide rising.
Frequently asked questions
What scope ratio should I use?
Around 5:1 for all-chain in calm conditions; 7:1 or more for rope rode or heavy weather.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.