Tide Time Calculator

Estimate water levels and tide changes throughout the day using chart data.

1. Known Tide Point

Enter the last known high tide from a local chart.

Known High Tide Time
2. Water Levels
High Water Level ft
Low Water Level ft
3. Current Status
Check Level at Time
Estimated Current Level
5.50 ft
Tide is Falling (Ebb)
02:15 PM Next High Tide
(Approx)
08:08 PM Next Low Tide
(Approx)
Daily Tide Curve (24h)

How are tides calculated?

Tides are primarily caused by the gravitational pull of the moon and the sun on Earth's oceans. Because the Earth rotates, most coastal areas experience two high tides and two low tides every 24 hours and 50 minutes (a lunar day).

  • The Rule of Twelfths: This is a "rule of thumb" used by sailors to estimate the height of the tide at any time between high and low water. It assumes the tide rises/falls 1/12th in the 1st hour, 2/12ths in the 2nd, 3/12ths in the 3rd and 4th, 2/12ths in the 5th, and 1/12th in the 6th.
  • Spring Tides vs. Neap Tides: When the sun and moon align (New or Full Moon), we get "Spring Tides"-the highest highs and lowest lows. When they are at right angles, we get "Neap Tides" with less variation.
  • Note: This tool provides a mathematical estimate based on harmonic curves. Local geography, wind, and barometric pressure can significantly alter actual water levels. Always consult official local tide tables for navigation.