Anchor Holding Power Calculator
Estimate anchor holding capacity based on type, weight, and bottom conditions
Holding Power Analysis
Anchor Holding Ratios by Type
| Anchor Type | Sand | Mud | Grass |
|---|---|---|---|
| Rocna/Mantus | 40:1 | 25:1 | 15:1 |
| Delta | 30:1 | 20:1 | 10:1 |
| Danforth | 35:1 | 15:1 | 5:1 |
| CQR/Plow | 20:1 | 15:1 | 8:1 |
| Bruce/Claw | 20:1 | 18:1 | 10:1 |
Ratios show holding power as multiple of anchor weight. Values are approximate averages from testing.
About Anchor Holding Power
Holding Ratio: The ratio of holding power to anchor weight. A 35 lb anchor with 30:1 ratio in sand provides approximately 1,050 lbs of holding power when properly set.
Wind Load: Wind load on a boat increases with the square of wind speed. A 40-knot wind creates 4x the load of a 20-knot wind.
Setting the Anchor: These calculations assume a properly set anchor. Always back down on the anchor to ensure it's well set. Holding power can be near zero if the anchor isn't set.
Safety Factors: Always maintain a minimum 2:1 safety margin for normal conditions, 3:1 or more for storm conditions or when leaving the boat unattended.