How Mira calculates a birth chart

A transparent overview of the birth details, astronomical positions, zodiac, houses, and aspect rules used to create a Mira natal chart.

Inputs and astronomical positions

Mira starts with birth date, local birth time, and place. The place provides latitude, longitude, and time-zone context. From the corresponding instant, the app calculates tropical zodiac positions for the major planets and points used in the chart.

If the time is missing or approximate, the interface should preserve that uncertainty. The rising sign, Midheaven, and houses are especially time-sensitive.

Zodiac, houses, and aspects

Mira uses the tropical zodiac and a consistent house method in the product calculation. Aspects are found by comparing planetary longitudes with defined target angles and allowed orbs. Retrograde labels come from apparent motion relative to Earth.

Different astrology traditions can choose different zodiacs, house systems, points, and orb limits. A different result does not automatically mean one calculator is broken; first compare the settings and birth data.

Calculation is not validation of meaning

Astronomical geometry can be calculated reproducibly. The claim that a placement describes personality or causes events belongs to astrology’s symbolic tradition and is not established by the calculation itself.

Mira therefore presents chart language as reflection rather than diagnosis or fate. If a description does not fit, you do not need to make yourself fit it.

One small action

Check the birth date, local time, place, zodiac, and house settings before comparing two chart results.

Journal prompt: Which parts of a chart are calculated facts, and which parts ask for interpretation?