J 40
Boat highlights
J 40 is currently estimated in the Decent band with an SBP score of 89.
Length overall
43.3 ft
Primary sail area
1,033 ft²
Displacement
16,755 lbs
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Performance Analysis
Detailed performance metrics and polar diagram for J 40.
Methodology note: SBP scores, polar diagrams, hull-speed values, and derived ratios are estimates. Use them for comparison and planning support—not as a substitute for manufacturer specifications, measured sea trials, rating certificates, professional weather routing, or safety margins. Review how we rate boats.
Performance Metrics
Speed Estimates
| Wind Speed (kn) | Beat VMG (kn) | Run VMG (kn) |
|---|---|---|
| 6 | 3.8 | 3.4 |
| 8 | 4.5 | 4.4 |
| 10 | 5.1 | 5.3 |
| 12 | 5.4 | 6.1 |
| 14 | 5.6 | 6.8 |
| 16 | 5.6 | 7.4 |
| 20 | 5.7 | 8.3 |
Polar Diagram
Wind Speed (kn)
Key Specifications
Explore the hull dimensions and sail plan for J 40.
Dimensions
Sails
Construction ratios
Discussion
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Log in to commentData sources and methodology
Published specifications are kept separate from calculated ratios and estimated performance. SBP and speed outputs are model-based estimates, not owner ratings or certified handicaps.
- Specifications
- verified
- Ratios
- derived
- Performance
- estimated
Last checked: 27 Aug 2026. Source: J Boats official website. Read the SBP methodology.
