# Tide Calculator Estimate local tide height and upcoming high/low tides from a known reference high tide. > Canonical page: https://elysiatools.com/en/tools/tide-calculator - **Category:** Geography - **Keywords:** tide, tide calculator, high tide, low tide, tidal height, coastal planning, marine, semidiurnal, diurnal ## Overview An offline tide-planning calculator that estimates tide state from a known local high-tide reference plus an average tidal cycle. It is designed for rough planning when you know one recent local high tide and the typical high/low water levels, but do not have harmonic-station data available. The model supports semidiurnal, mixed semidiurnal, and diurnal cycles, and clearly labels itself as an estimate rather than a navigation-grade forecast. ## Inputs - **参考高潮时间** (text): 2026-06-30 06:15 - **目标日期** (date) - **目标时间（HH:MM）** (text) - **潮汐周期类型** (select) - **平均高潮位** (number) - **平均低潮位** (number) - **潮高单位** (select) - **预测天数** (number) - **地点标签（可选）** (text) ## When to use - When planning coastal activities in areas lacking active harmonic tide station data. - When you need a quick, offline estimate of tide heights based on a single known recent high tide. - When comparing general tidal trends across semidiurnal, mixed, or diurnal cycles for preliminary trip planning. ## How it works - Enter a known reference high tide date and time along with your target date and time. - Select the tidal cycle type (semidiurnal, mixed, or diurnal) and input the mean high and low water levels. - Specify the height unit (meters or feet) and the number of prediction days (up to 5 days). - Generate the HTML report showing the estimated tide height at the target time and a schedule of upcoming tidal events. ## Use cases - Estimating water depth for beachcombing or coastal hiking during low tide. - Roughly planning kayak launch times based on local high tide observations. - Generating a multi-day tide estimate table for remote coastal locations without cellular service. ## Frequently asked questions ### Can this calculator be used for official marine navigation? No, this tool provides rough estimates based on average cycles and should not be used for navigation-grade forecasting. ### What tidal cycle types are supported? It supports semidiurnal (approx. 12h 25m), mixed semidiurnal, and diurnal (approx. 24h 50m) cycles. ### What inputs are required to run the calculation? You must provide a reference high tide timestamp and a target date; other parameters use default values if not specified. ### How many days of tide predictions can I generate? You can generate predictions for a range of 1 to 5 days from the target date. ### Does this tool require an active internet connection to work? 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