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Reference table

Ellipse Table: Area by Semi-major axis (a)

Reference table of area for Ellipse across a range of semi-major axis (a) values — exact, engine-computed figures you can read off at a glance.

By Vikram Iyer, M.Sc Mathematics · Updated Jun 2026 · 1 min read

This ellipse reference table shows the area for a range of semi-major axis (a) values, assuming a semi-minor axis (b) of 3 units. Every figure is computed with the same engine that powers our Ellipse Calculator, so the numbers are exact.

Semi-major axis (a)AreaCircumference (approx.)
1.3 units12.252214.0420
2.5 units23.561917.3145
3.8 units35.814221.4368
5 units47.123925.5270
7.5 units70.685834.5192
10 units94.247843.8567
15 units141.371763.0168
25 units235.6194102.1094
35 units329.8672141.5767
50 units471.2389201.0289

How to use this table

Find the row closest to your semi-major axis (a) and read across to the area. For a value between two rows, the real figure sits between them — or enter your exact numbers in the Ellipse Calculator for a precise answer.

Need a value that is not in the table? — the Ellipse Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring math calculators with these tools: Margin of Error Calculator, Sample Size Calculator, Confidence Interval Calculator, Coefficient of Variation Calculator, Regular Heptagon Area Calculator.

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Frequently asked questions

Each cell is computed with the standard formula using exact arithmetic — the same calculation behind our Ellipse Calculator — so every figure is accurate for the stated assumptions.

Yes. The table covers common semi-major axis (a) values; for any exact figure, enter your own numbers in the Ellipse Calculator.

Vikram Iyer · M.Sc Mathematics

Vikram Iyer is a mathematics educator with over fifteen years of teaching experience, specialising in making quantitative concepts clear and practical for everyday use.