What size windlass, anchor & chain do I need?
Answer four quick questions and we'll size your complete ground tackle system — anchor weight, chain size, how much rode to carry and the right Maxwell windlass — using Maxwell's official sizing method and standard anchoring scope practice.
How the sizing method works
Step 1 — plan the rode. Rode length comes from scope: the ratio of rode paid out to the distance from your bow roller to the seabed (water depth plus bow height). All-chain rodes typically use 3:1 for calm day stops, 5:1 for typical overnight anchoring and 7:1 when it's exposed; rope/chain rodes need roughly two ratios more. The chain size itself follows boat length per Maxwell's chain selection guide.
Step 2 — weigh the tackle. Anchor (MAXSET sized to your boat, one size up for exposed conditions or heavy displacement) plus chain and rope at standard DIN766 / 8-plait nylon weights per metre.
Step 3 — apply Maxwell's rule. Required maximum pull = ground tackle weight × 3. The worked example in Maxwell's own catalogue: 30 kg anchor + 45 kg of chain + 12 kg of rope = 87 kg, so the windlass needs at least 261 kg of pull.
Worked example (from the Maxwell catalogue):
30 kg anchor + 18 m/60 ft chain (45 kg) + 61 m/200 ft rope (12 kg)
Ground tackle = 87 kg → × 3 = 261 kg maximum pull
→ RC8-8, RC10-8, HRC10-8 or VW1000 all qualify
Step 4 — cross-check the chart. Maxwell also publishes advised boat-length bands for every model, with separate bands for light and heavy displacement vessels. The calculator checks both — Maxwell calls the chart a basic guide, so where they disagree we follow the more demanding of the two.
The result is guidance, not gospel: locker depth, deck layout and how you actually anchor all matter, which is why Luxfords reviews every selector result before quoting.
Sizing FAQs
How is the required windlass size calculated?
Maxwell's published method: add up your ground tackle weight (anchor + chain + rope), then require the windlass's maximum pull to be at least three times that figure. The calculator first plans your rode from scope and depth, weighs it with standard DIN766 chain and 8-plait nylon figures, adds the recommended MAXSET anchor, and applies the 3× rule — then cross-checks the result against Maxwell's boat-length selection chart for your displacement class.
Why three times the ground tackle weight?
A windlass's working load — what it sustains during normal retrieval — is roughly one third of its maximum (stall) pull. Specifying maximum pull at 3× ground tackle weight means the windlass works at a comfortable load while hauling your complete rode and anchor, with reserve for breaking the anchor out of the bottom.
Should I size for the boat I have or the anchoring I do?
Both — that's why the calculator asks where and how deep you anchor. A 10 m boat that day-anchors in 5 m of sheltered water needs far less rode (and a smaller windlass) than the same boat anchoring overnight in 15 m off an exposed coast. Heavier displacement and high windage also push the requirement up — when in doubt, go one size up; nobody has ever complained their windlass was too powerful.
Does the windlass hold the boat at anchor?
No — and this matters. The windlass is designed to lift the rode and anchor, not to take anchoring loads. Once set, the load must be transferred to a chain stopper or snubber, and the anchor should be secured the same way under way. That's why every result in this calculator includes a stopper or snubber in the system.