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Distance Modulus (Star Magnitude) Calculator

Find absolute magnitude from apparent magnitude and distance.

Inputs

Results

Absolute magnitude4.83

Chart

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How to use the distance modulus calculator

Find absolute magnitude from apparent magnitude and distance. Enter apparent magnitude, distance in the fields above; the absolute magnitude is computed instantly and plotted on the chart so you can see how the answer changes.

Formula

Absolute magnitude = m-5 ร— log10(d / 10)

Variables

  • m โ€” Apparent magnitude
  • d โ€” Distance (parsecs)

Worked example

With apparent magnitude = 4.83, distance = 10 parsecs, the calculator gives absolute magnitude โ‰ˆ 4.83.

Frequently asked questions

What is the formula for the distance modulus calculation?

Absolute magnitude = m-5 ร— log10(d / 10). Here m is apparent magnitude, d is distance (parsecs).

What inputs do I need for the distance modulus (star magnitude) calculator?

You need apparent magnitude, distance in parsecs. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.

How do I use this calculator?

Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.

Is the result exact?

Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.

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