ANCHORING GUIDE · CALCULATOR
Muir Windlass Selection Tool
Enter your chain, boat length and anchor weight, or pick the Lewmar, Maxwell, Lofrans or Quick you're replacing, and see which Muir windlasses, drum winches and capstans fit, each checked against Muir's 3× pull rule.
Size your windlass
Windlass type
Think about your deck space, anchoring arrangement and anchor locker.
Chain size & standard
Match your existing chain, or the chain you plan to buy, to a compatible gypsy.
Your boat
Length, weight and windage decide the size class. If in doubt, go up a size.
Ground tackle check
Muir recommends the maximum pull be at least 3× the total weight of anchor + chain.
23 matching Muir models (+6 rope-only capstans)
Takes 10–12 mm (3/8"–1/2") line — dock lines, warping and pot hauling; no chain gypsy. Compare the 50 kg work load to your heaviest line pull.
Takes 10–12 mm (3/8"–1/2") line — dock lines, warping and pot hauling; no chain gypsy. Compare the 110 kg work load to your heaviest line pull.
Takes up to 12 mm (1/2") line — dock lines, warping and pot hauling; no chain gypsy. Compare the 45 kg work load to your heaviest line pull.
Takes 10–14 mm (3/8"–9/16") line — dock lines, warping and pot hauling; no chain gypsy. Compare the 149 kg work load to your heaviest line pull.
Takes 12–19 mm (1/2"–3/4") line — dock lines, warping and pot hauling; no chain gypsy. Compare the 395 kg work load to your heaviest line pull.
Takes 14–25 mm (9/16"–1") line — dock lines, warping and pot hauling; no chain gypsy. Compare the 510 kg work load to your heaviest line pull.
Guide only. The specifications above apply to vessels operating in safe weather conditions. Where a vessel is used for charter or commercial purposes, for extended offshore cruising in rugged conditions, or sits at the upper limit of a windlass size, select a larger model. All systems assume a chain stopper or snubber takes the load once anchored. Contact your Muir representative to confirm your selection.
HOW IT WORKS
How the Windlass Selection Tool Works
The Windlass Selection Tool below uses your windlass type, chain standard and size, vessel length and ground tackle to match you to suitable Muir models, checked against Muir’s own sizing rule: maximum pull should be at least three times the combined weight of your anchor and chain. Replacing another brand? Pick your current model and the tool starts from the Muir equivalent.
Closest Match First
Results are ordered so the model sized closest to your vessel appears first, with a tick, warning or cross showing how its maximum pull compares with three times your ground tackle.
When to Size Up
Larger models follow. Choose one if your vessel is heavy or has high windage, sits at the top of a model's size range, or you plan to add chain later. The tool flags these cases for you.
Planning to upgrade later? If you expect to add more chain or upgrade your anchor in future, enter those values now so the Windlass Selection Tool recommends a windlass with sufficient power for your desired setup.
Gypsies are chain-specific. While Muir offers a full range of gypsies, changing your chain type may require a new one. Even chains of the same nominal size can differ in standard or pitch — always confirm compatibility before purchasing to avoid unnecessary costs.
COMMON QUESTIONS
Windlass Selection Tool FAQs
What information do I need to use the Windlass Selection Tool?
Vessel length is the main one. Adding your chain standard and size narrows the results to models with a matching gypsy, and chain length plus anchor weight lets the tool check each model’s maximum pull against Muir’s 3× rule. If you are replacing another brand, you only need its model name.
Why does the tool show more than one model?
The closest match for your vessel is listed first. Larger models are shown as well, because a heavy or high-windage vessel, a boat at the top of a size range, or plans to add more chain are all reasons to go up a size.
Will any gypsy fit my chain?
No. Gypsies are specific to chain standards and dimensions. Even chains of the same nominal size can differ in standard or pitch, so always confirm compatibility before purchasing.
Should I size up if I plan to upgrade my anchor or chain later?
Yes. If you expect to add more chain or upgrade your anchor in future, enter those values now so the Windlass Selection Tool recommends a windlass with sufficient power for your desired setup.
Not Sure Which Result Fits?
Not sure which result the Windlass Selection Tool gave you, or want a second opinion? Contact the Muir team for personalised recommendations, dealer locations, and technical support.
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