Anchor Chain Weight by Size: kg/m and lb/ft Chart

Before you replace your chain, add more of it or buy a windlass, there is one question worth answering with numbers: how much does it weigh? Weight decides whether the windlass lifts it without strain, how far the bow goes down and whether the chain locker can take it. Here are the weights per meter for the most common sizes, the totals for 30, 50 and 70 m, and what to check so it fits your gypsy.

Weight chart by size (DIN 766)

DIN 766 is the most common short-link calibrated chain on European-built boats, and many boats imported into the US still carry it. These are the reference values:

Size	kg/m	lb/ft	Inside link length / pitch (mm)
6 mm	0.8	0.54	18.5
8 mm	1.4	0.94	24
10 mm	2.25	1.51	28
12 mm	3.2	2.15	36
13 mm	3.8	2.55	36
14 mm	4.4	2.96	41

Real weights vary by 5-8% between manufacturers, mainly because of the thickness of the galvanizing. The 13 and 14 mm figures are typical industry values: if you need precision, check your manufacturer's spec sheet.

Total weight for 30, 50 and 70 m

Multiply the weight per meter by the length you carry. For the most common lengths (dry weight, kg with lb in brackets):

Size	30 m (98 ft)	50 m (164 ft)	70 m (230 ft)
6 mm	24 (53)	40 (88)	56 (123)
8 mm	42 (93)	70 (154)	98 (216)
10 mm	68 (149)	113 (248)	158 (347)
12 mm	96 (212)	160 (353)	224 (494)
13 mm	114 (251)	190 (419)	266 (586)
14 mm	132 (291)	220 (485)	308 (679)

In seawater, steel loses about 13% of its weight to buoyancy: 50 m of 10 mm weighs 113 kg in the locker and about 98 kg hanging. When you weigh anchor, the windlass only lifts the chain that is hanging (plus the anchor), but size it with room to spare: a common manufacturer rule is a maximum pull of about three times the weight of the anchor plus all of the chain.

DIN 766, ISO 4565 and G43 are not interchangeable

Two chains of the same size may not fit the same gypsy. What matters is the pitch, the inside length of each link, which has to match the pockets of your windlass gypsy.

• DIN 766: the German calibrated chain standard, the most widespread in Europe.
• ISO 4565: the same as DIN 766 in 6 and 8 mm, but 10 mm is different: a 30 mm pitch (against 28) and about 2.3 kg/m. At 12 mm they match again (36 mm).
• G43 (High Test, formerly called G40): the standard inch chain in the US. Stronger for its size and with different pitches.

G43	kg/m	lb/ft	Pitch (mm)
1/4" (6.35 mm)	1.09	0.73	21.6
5/16" (7.94 mm)	1.53	1.03	26.2
3/8" (9.53 mm)	2.2	1.48	31
7/16" (11.11 mm)	3.07	2.06	35.6
1/2" (12.7 mm)	3.82	2.57	40.4

If you do not know which chain you have, measure the inside length of 10 links in a row and divide by 10: you get the pitch far more accurately than by measuring a single link.

How chain weight affects bow trim

The chain lives in the forward locker, the point farthest from the middle of the boat. There, weight counts double: it pushes the bow down and makes the boat pitch more, because it has to lift that weight with every wave.

An example: 50 m of 10 mm (113 kg) plus a 15 kg anchor adds up to almost 130 kg (about 285 lb) right at the tip of the boat. That is like having two adults sitting on the bow pulpit at all times. On a 30-33 ft sailboat you feel it when you motor into a head sea, and you see it on the waterline.

• Do not carry more chain than you use. If you always anchor in less than 10 m (33 ft), you may have 20 m to spare.
• Combine chain and rope if your windlass handles it: a length of chain at the anchor and the rest in nylon weighs far less.
• Do not downsize by eye. Thinner chain weighs less, but it is also weaker. Our anchor chain guide explains how to choose the size for your boat.

Galvanized or stainless

Size for size, stainless steel chain weighs practically the same as galvanized: steel is steel. Everything else is different.

• Hot-dip galvanized: the standard choice. Cheaper, easy to find in DIN 766, ISO 4565 and G43, and it can be regalvanized when the zinc wears off.
• Stainless (316): does not stain the deck or the locker, looks good and stacks better in the locker. It costs several times as much and quality varies a lot between brands: insist on calibrated chain and check the pitch just as you would with galvanized.

To compare models, sizes and prices, see the anchor chains we compared. And to know how much of that chain to let out each time, read our guide on how to anchor.