What Size Yacht Fender
Do I Need?
If you've ever stood on a dock watching someone squeeze undersized fenders between a 60-footer and a concrete wall, you know why this question matters. Getting fender size right isn't complicated — but getting it wrong can cost you thousands in gelcoat repairs, or worse.
We've been making and selling yacht fenders since 1986. Here's what we've learned.
The One-Inch Rule
The industry standard is simple: one inch of fender diameter for every four to five feet of yacht length. That's for cylindrical fenders, which is what most yacht owners use.
for every 4 to 5 feet of yacht length
A 50-foot yacht needs fenders with at least a 10–12 inch (25–30 cm) diameter. A 30-footer needs around 6–8 inches. A 100-footer needs around 20–24 inches.
This rule is a starting point — not a ceiling. There are three reasons to go up a size:
- Displacement matters more than length. A heavy-displacement trawler yacht at 50 feet puts far more load on fenders than a lightweight racing sailboat of the same length. If your boat is heavy for its size, go one fender size up.
- Mooring conditions matter. A calm lake marina and an exposed Atlantic-facing berth are completely different environments. If you regularly deal with swell, tidal range, strong crosswinds, or heavy wash from passing traffic, bigger fenders are cheap insurance.
- Power yachts vs. sailing yachts. Power yachts are almost always heavier at the same length. A 50-foot sailing yacht might get away with 10″ fenders. A 50-foot flybridge motor yacht should move up to 12″ or even 14″.
Yachtfend Size Reference
Based on our 18-size range, this is the sizing reference we recommend for most owners and captains.
| Yacht Length | Recommended Fender Size |
|---|---|
| 30–50 ft | 12″ fenders (30 × 65 cm) |
| 40–70 ft | 14″ fenders (36 × 85 cm) |
| 50–80 ft | 16″ fenders (41 × 85 cm or 41 × 115 cm) |
| 80–125 ft | 20″ fenders (46 × 85–153 cm) |
| 100–200 ft | 24″ fenders (61 × 85–153 cm) |
| 150–300 ft | 38″ fenders (100 × 170–245 cm) |
Need the full breakdown? View our full fender size chart →
What About Fender Length?
Diameter gets all the attention, but length matters too — especially if your yacht has high freeboard. The fender needs to cover enough of your hull's vertical surface to actually protect it as the yacht moves with waves, tide, and wash.
For yachts with particularly tall topsides — many modern flybridge designs, for example — choose a longer fender option. At Yachtfend, most diameter sizes are available in two or three length options for exactly this reason.
How Many Fenders Do You Need?
A useful rule of thumb: one fender per 10 feet of waterline length, with a minimum of three.
fenders as a practical minimum.
fenders for normal marina use.
fenders depending on berth and conditions.
size the setup to the yacht and mooring plan.
If you do Med-style stern-to mooring — which most of us in the Mediterranean do — you'll want at least six regardless of yacht size. You need coverage on both sides for the approach, plus at least two for the quay contact.
Tip from 35+ years on the water: Always carry two spare fenders. The day you need them and don't have them is the day something goes wrong.
The Honest Answer
The real answer to "what size fender do I need?" is this: when in doubt, go one size bigger. Fenders are one of the cheapest pieces of gear on a yacht relative to the damage they prevent. A single gelcoat repair can cost more than a full set of properly sized fenders.
If you're not sure, email us at sales@yachtfend.com with your yacht model, length, beam, and where you typically moor. We've been doing this since 1986 — we'll point you in the right direction.
Need Help Choosing the Right Fender Setup?
Browse the full range or start with a ready-built package designed around your yacht size and fender diameter.