Sail Trim by Point of Sail Calculator
Get sail trim angle and traveler position for any point of sail.
Reference table for close-hauled, beam reach, broad reach, and run with twist guidance.
Sail Trim Settings
Sail Trim by Point of Sail
Each point of sail requires different sail trim. The fundamental rule is to ease the sails until they just luff, then trim until the luff stops — that’s the optimal angle for that wind direction.
Standard points of sail:
| Point | TWA Range | Sail Trim |
|---|---|---|
| In irons (no go zone) | 0-30° | Cannot sail |
| Close-hauled | 30-50° | Sails fully sheeted in, traveler high |
| Close reach | 50-80° | Sails slightly eased |
| Beam reach | 80-110° | Sails about half-sheeted |
| Broad reach | 110-150° | Sails well eased, boom away |
| Running | 150-180° | Boom out 90° to wind, wing on wing if rigged |
Mainsail trim by point:
- Close-hauled: main sheeted hard, traveler centered or to windward, vang pulled
- Close reach: ease sheet 1-2 ft, traveler down
- Beam reach: boom about 30-45° from centerline
- Broad reach: boom 60-80° from centerline, vang firm
- Running: boom near 90°, watch for accidental gybe
Headsail trim:
- Genoa cars: forward in light air (more depth) / aft in heavy (flatter sail)
- Tell tales: outer (windward) and inner (leeward) tell tales should both stream aft
- Inner luffing → ease sheet
- Outer luffing → trim sheet
Sail twist guidelines:
- Light air (under 8 kts): more twist (top of sail eased more) for flow
- Medium air (8-15 kts): standard twist, both tell tales streaming
- Heavy air (15+ kts): less twist (top of sail more flat) for power control
Vang and Cunningham:
- Vang: controls leech tension on running and reaching — pull harder downwind
- Cunningham: flattens the sail in heavy wind by pulling luff down
- Outhaul: flattens the bottom of the main — pull harder in heavy air
Wind speed considerations:
| Wind Speed | Reaching | Running |
|---|---|---|
| Under 6 kts | Power up — eased sails, deep | Move weight forward, full main |
| 6-12 kts | Standard trim | Wing-on-wing, flat seas best |
| 12-18 kts | First reef option, balanced | Easy gybe — watch boom |
| 18-25 kts | Reef + smaller jib | Reef + small chute |
| 25+ kts | Reef + storm jib | Storm sails, careful gybes |
The “tell tale rules”:
- Both windward and leeward tell tales streaming aft = trimmed correctly
- Windward tell tale lifting / fluttering = sail too tight; ease sheet
- Leeward tell tale fluttering = sail too loose; trim sheet
- Top tell tale lifting = too much twist; pull vang or sheet
- All tell tales fluttering = bad shape; check halyard tension
Common mistakes:
- Over-trimming (everyone’s default in light air) — boat slows, points lower
- Forgetting traveler — main sheet alone doesn’t give full control
- Wrong genoa car position for wind speed
- Not adjusting for wind shifts — set and forget = lost speed