Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Rode to deploy
189
feet
Total vertical height
27.0
Approx swing radius (ft)
219
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter water depth (ft).
- 2Enter bow height above water (ft).
- 3Enter expected tide rise (ft).
- 4Enter scope ratio (x:1).
- 5Read your rode to deploy on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Scope is the ratio of rode deployed to the vertical distance from bow roller to seabed. Under 5:1 in wind is how boats drag.
Worked example
Using the values the calculator loads with:
Inputs
- Water depth: 20 ft
- Bow height above water: 4 ft
- Expected tide rise: 3 ft
- Scope ratio (X:1): 7
Results
- Rode to deploy: 189
- Total vertical height: 27
- Approx swing radius (ft): 219
What each field means
Inputs
- Water depth (ft)
- The water depth used in the calculation, measured in ft. Starts at 20 ft so you have a working example on load.
- Bow height above water (ft)
- The bow height above water used in the calculation, measured in ft. Starts at 4 ft so you have a working example on load.
- Expected tide rise (ft)
- The expected tide rise used in the calculation, measured in ft. Starts at 3 ft so you have a working example on load.
- Scope ratio (X:1)
- The scope ratio (x:1) used in the calculation. Starts at 7 so you have a working example on load. Accepted range: 3–12.
Results
- Rode to deploy
- feet
- Total vertical height
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Approx swing radius (ft)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the anchor rode & scope calculator work?
Scope is the ratio of rode deployed to the vertical distance from bow roller to seabed. Under 5:1 in wind is how boats drag. The underlying maths is: Rode = (depth + freeboard + tide) × scope ratio.
What do I need to enter?
4 values: water depth, bow height above water, expected tide rise, and scope ratio (x:1). Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the rode to deploy result mean?
feet It is returned as a decimal number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary.
Who is this tool for?
It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Anchor Rode & Scope Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/anchor-rode-scope
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/anchor-rode-scope" target="_blank" rel="noopener">Anchor Rode & Scope Calculator — RevenueLab</a> (2026).</p>
Source: [Anchor Rode & Scope Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/anchor-rode-scope) (2026).