Free Davison Chart Calculator
Enter two sets of birth details to calculate the Davison relationship chart for the midpoint between the two births.
What is a Davison relationship chart?
A Davison chart (also called a Davison relationship chart) is a chart cast for the exact midpoint in time and space between two births. Unlike the composite chart, which averages planetary positions to create an abstract chart, the Davison chart represents a real calculated moment and location. Many astrologers use that structure when they want to compare relationship themes with transits, progressions, or returns.
The technique was developed by British astrologer Ronald C. Davison in the 1970s. The midpoint date is calculated by averaging the Julian Day Numbers of both births, the midpoint location is the geographic average of both birthplaces, and a natal-style chart is cast for that derived moment and place. The result should be read as a relationship chart layer, not as proof of compatibility or fate.
How the Davison chart differs from the composite chart
The composite chart is built by averaging the positions of each planet in two natal charts: your Sun's longitude plus their Sun's longitude divided by two, and so on for every planet, angle, and point. The result is a mathematical abstraction: a chart that represents the relationship symbolically but does not correspond to any real moment in time or location in space. Because of this, applying transits or progressions to a composite chart is debated among practitioners.
The Davison chart solves this by identifying the actual midpoint moment between two births and casting a genuine natal chart for that time and place. Because it is cast for a calculated time and location, many astrologers use it with transits, secondary progressions, and returns when reviewing relationship timing. Astrologers often use both: the composite for a symbolic portrait and the Davison for a time-and-space midpoint layer. Compare the two outputs side by side using our composite chart calculator, and read the full methodological breakdown in our Davison vs. composite chart guide.
Key Davison chart placements to look for
Because the Davison chart is cast like a natal chart, many astrologers begin with the Sun as a core identity prompt, the Moon for emotional texture, and Venus and Mars for attraction, desire, and conflict style. The Ascendant, when both birth times are exact, describes how the relationship presents itself to the world.
Pay special attention to planets in angular houses (1st, 4th, 7th, 10th), which tend to stand out in chart interpretation. Saturn placements can show where the relationship asks for maturity and commitment. Jupiter can show where it expands more easily or feels generous. The aspects table helps you judge whether the chart's energies flow smoothly (trines, sextiles) or create productive tension (squares, oppositions) that drives growth.
Related Free Tools
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Descendant Sign Calculator
Find your Descendant sign and discover what you seek in partnerships, relationships, and one-on-one dynamics.
Frequently Asked Questions
What is a Davison chart?
A Davison chart, also called a Davison relationship chart, is calculated from the midpoint in time and space between two births. Unlike a composite chart's abstract planetary midpoints, the Davison chart is cast for a calculated moment and location, so many astrologers use it with transits and progressions.
How is a Davison chart different from a composite chart?
Both are relationship charts, but they are constructed differently. A composite chart averages each planet pair's positions. A Davison chart finds the midpoint date, time, and location between two births, then casts a chart for that moment and place. Transits and progressions are more straightforward on the Davison chart, while their use on composites is debated.
Can I run transits to a Davison chart?
Many astrologers do. Because the Davison chart is cast for a calculated time and location, it can be compared with transits, progressions, and returns when reviewing relationship timing. Treat those contacts as timing testimony, not as guaranteed milestones.
Do I need exact birth times for a Davison chart?
Exact birth times produce the most accurate Davison chart, particularly for the midpoint time calculation and house placements. Without birth times, the midpoint date and planet sign positions are still reliable. You can indicate your confidence level for each person's birth time.
How accurate is the Davison chart calculator?
The midpoint date, time, and geographic coordinates are derived from both birth data sets, then a natal-style chart is cast for that derived moment and location. Exact birth times matter most for the midpoint time, Ascendant, houses, and angular placements.
Who developed the Davison chart technique?
The Davison relationship chart was developed by British astrologer Ronald C. Davison in the mid-20th century. His approach of finding the temporal and spatial midpoint between two births offered an alternative to the composite chart that produced a chart anchored in real time and space.
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