🌊
Tidal Height — Rule of Twelfths
PROEstimate tidal height at any time between HW and LW using the rule of twelfths.
Capt. Rob StentVerified
MCA Yachtmaster Ocean, MNZ Coxswain (restricted)
Offshore sailing instructor and maritime educator with 30 years of blue-water passages. Author of coastal navigation guides for NZ waters.
Numly Pro
Unlock Tidal Height — Rule of Twelfths
Get full results, advanced insights and unlimited access with Numly Pro.
- Access this and 300+ professional calculators
- Advanced insights and detailed breakdowns
- Engineering, trading, clinical and chemistry tools
- Save calculations and track history
- Export results as PDF
- No ads — ever
NZ$9.99/month after trial · Cancel anytime
Related calculators
⚓🧭⛵
Anchor Scope Calculator
Calculate required anchor rode scope for safe holding at depth.
Nautical Distance / Speed / Time
Solve any two of distance (nm), speed (knots) and time for passage planning.
Hull Speed Calculator
Calculate the theoretical hull speed for a displacement vessel from waterline length.
Was this helpful?0 found helpful