How to Use Tide Calculator
Enter a date, latitude, longitude, and mean tidal range. The Tide Calculator estimates two high tides, two low tides, and a rough range for the selected day.
The location fields are used for a simplified astronomical phase estimate, not for reading a local tide station. The mean tidal range scales the displayed high and low water estimates.
Use this as a classroom or planning illustration only. Navigation, boating, fishing safety, coastal flooding, and port operations require official tide tables or gauge data.
Formula & Theory — Tide Calculator
The Tide Calculator uses the following formula or scoring rule:
high tide phase ≈ lunar age × 0.84 + longitude/15 + offset
low tide ≈ high tide + 6.21 hThe simplified model uses lunar age to approximate the Moon-driven tidal phase and longitude to shift timing. A semidiurnal pattern places low tides about 6.21 hours after high tides.
The range estimate is adjusted by a lunar-cycle factor, so spring-neap variation appears in a rough way. It does not include coastline shape, water depth, storm surge, wind setup, pressure, or local harmonics.
Real tide prediction depends heavily on local harmonic constants. Two places at similar longitude can have very different tide timing and range.
Use Cases for Tide Calculator
The Tide Calculator is useful in specific situations such as:
- demonstrating the relationship between Moon phase and tide timing
- building a simple geography classroom example
- roughly comparing dates in a lunar cycle
- explaining why official local tide tables are necessary for safety