Skip to main content
Calcimator

Tide Height Calculator

Estimate the current tide height using the Rule of Twelfths, plus time to next high and low tide.

Inputs

ft
ft
hrs
hrs

Results

Current Tide Height

5.15 ft

≈ 10 smartphones

Tide Range6 ft
Next High Tide In9.42 hrs
Next Low Tide In3.21 hrs
Current Rate of Change1.45 ft/hr
Tide Falling (1=yes, 0=no)1
How to Use This Calculator
  1. Look up today's high tide height and low tide height in feet from a tide chart or app.
  2. Enter the hours elapsed since the last high tide.
  3. Leave the tidal period at 12.42 hours for standard semidiurnal tides, or adjust for your location.
  4. Read the current tide height using the Rule of Twelfths calculation.
  5. Check the time to next high and low tide to plan passages over shallow bars or inlets.

How the result changes with Tidal Period

Tidal PeriodCurrent Tide Height
7.92.94 ft
135.35 ft
186.5 ft
236.93 ft

What each input means

High Tide Height
Height of the last or next high tide in feet above chart datum.
Low Tide Height
Height of the last or next low tide in feet above chart datum.
Hours Since High Tide
Number of hours elapsed since the last high tide.
Tidal Period
Full tidal cycle period in hours (12.42 for typical semidiurnal tide).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    High Tide Height = 8, Low Tide Height = 2, Hours Since High Tide = 3, Tidal Period = 12.42 = 4 input(s) provided
  2. Calculate Current Tide Height
    Current Tide Height
    5.15 = 5.15
  3. Calculate Tide Range
    Tide Range
    6 = 6
  4. Calculate Next High Tide In
    Next High Tide In
    9.42 = 9.42

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Marine & Boating

Marine Fuel Consumption Calculator

Calculate fuel needed, trip time, cost, and range for your boat based on engine specs, speed, and distance.

Marine & Boating

Anchor Line (Rode) Calculator

Calculate the proper anchor line scope, chain length, and rope length based on water depth and conditions.

Oceanography

Tidal Range Predictor

Predict spring and neap tidal ranges from mean tidal range, lunar phase, and solar declination factor.

Marine & Boating

Boat Displacement Calculator

Estimate your boat's displacement, waterline area, and theoretical hull speed from hull dimensions and type.

More in Aviation, Marine & Transport.