Tidal ranges vary throughout the lunar month because the relative positions of the Earth, Moon, and Sun change. When the Sun and Moon are aligned (new or full moon), their gravitational forces combine, producing the highest tides known as spring tides.
Conversely, when the Sun and Moon are at right angles (first and last quarter), their forces partially cancel, resulting in the lowest tides called neap tides. The difference between spring and neap tidal ranges is called the tidal range amplitude.
For many practical applications, such as navigation or coastal engineering, it is useful to estimate the tidal range at any intermediate lunar phase. Assuming a linear relationship, the range can be interpolated between the measured neap and spring values using a simple proportion.
What are spring tides?
How do neap tides differ from spring tides?
What is tidal range amplitude?
How often do neap tides occur in a year?
Can this calculator help with planning maritime activities?
What factors affect tidal ranges besides the Sun and Moon?
Is there a difference in tidal patterns between oceans?
Results are for informational purposes only and do not constitute professional advice.