Eclipse Calculator
List the upcoming solar and lunar eclipses and see exactly what each one looks like from where you are: whether it is visible, the local start, maximum and end times, how much of the Sun or Moon is covered, and an animation of the event.
Last updated:
Upcoming eclipses
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Local circumstances
Global data
⚠️ Never look at the Sun without certified solar eclipse glasses (ISO 12312-2) or a proper solar filter, except during the brief total phase of a total solar eclipse. Lunar eclipses are completely safe to watch.
How to use the Eclipse Calculator
- Set your location: pick a city, press Use my location, or type latitude and longitude.
- Choose the period to search (3 to 20 years) and whether you want solar, lunar or both.
- Press Find eclipses. Each eclipse in the list shows its type and whether you can see it.
- Select an eclipse to see local times, coverage, Sun or Moon altitude and the global data.
- Play the animation or drag the slider, then copy the details or download a calendar event.
How the eclipse calculator works
The tool finds every new moon and full moon in the period you choose, then checks whether the Moon is close enough to the ecliptic (its orbit's node) for an eclipse. For each candidate it computes the Sun's position from a truncated VSOP87 planetary theory and the Moon's from the ELP-2000/82 lunar theory, including nutation, aberration and the difference between Terrestrial Time and Universal Time (ΔT, about 69 seconds in the 2020s).
- Solar eclipses: the shadow axis is projected onto the fundamental plane through Earth's center. Its smallest distance from the center is gamma, and the umbral and penumbral cone radii decide whether the eclipse is total, annular, hybrid or partial. For your location the apparent Sun and Moon are computed with full parallax for your spot on the WGS84 ellipsoid, and contact times are where their apparent disks touch.
- Lunar eclipses: the radii of Earth's umbra and penumbra follow the classical formulas with the customary 2% enlargement for Earth's atmosphere: umbra = 1.02 × (0.99834 πMoon − sSun + πSun) and penumbra = 1.02 × (0.99834 πMoon + sSun + πSun), where π is horizontal parallax and s the Sun's semi-diameter.
- Coverage: obscuration is the overlapping area of the two disks divided by the Sun's area, so it is always a little lower than the magnitude.
Eclipse types at a glance
| Type | What happens | Where visible | Typical length |
|---|---|---|---|
| Total solar | Moon covers the whole Sun; corona appears, sky darkens | Narrow path, usually under 250 km wide | Totality up to about 7.5 minutes |
| Annular solar | Moon too far away to cover the Sun; a bright ring remains | Narrow path | Annularity up to about 12.5 minutes |
| Hybrid solar | Total along part of the path, annular elsewhere | Narrow path | Usually short, often under 2 minutes |
| Partial solar | Only part of the Sun covered | Large region either side of the path | About 1–3 hours from start to end |
| Total lunar | Whole Moon inside the umbra, turns red or copper | Entire night side of Earth | Totality up to about 1 h 47 min |
| Partial lunar | Part of the Moon enters the umbra; a dark bite appears | Entire night side of Earth | Up to about 3.5 hours |
| Penumbral lunar | Moon only in the faint penumbra; subtle shading | Entire night side of Earth | Several hours, hard to notice |
Tips for planning an eclipse trip
- Totality is all-or-nothing. Even 99% coverage looks completely different from a total eclipse. If the list says "Partial here" for a total eclipse, try a city closer to the point of greatest eclipse.
- Check the Sun's altitude. An eclipse low in the sky is easily blocked by hills, trees or haze; above about 20° is comfortable.
- Weather matters most. Look up cloud-cover climate for your chosen spot and keep a backup location within driving distance.
- Protect your eyes and camera. Use ISO 12312-2 eclipse glasses and a solar filter on lenses and binoculars for all partial phases.
- Lunar eclipses need only clear skies. Use the Moonrise and Moonset Calculator to see where the Moon will be in your sky.
Frequently asked questions
What is the difference between a solar and a lunar eclipse?
A solar eclipse happens at new moon when the Moon passes between the Sun and Earth and its shadow falls on part of Earth, so it is only visible from a limited region. A lunar eclipse happens at full moon when the Moon moves through Earth's shadow, and it can be seen from the whole night side of Earth.
What do magnitude and obscuration mean?
For a solar eclipse, magnitude is the fraction of the Sun's diameter covered by the Moon, while obscuration is the fraction of the Sun's area covered. A magnitude of 0.5 corresponds to roughly 40% obscuration. For a lunar eclipse, the umbral magnitude is the fraction of the Moon's diameter inside Earth's dark umbra; 1.0 or more means a total eclipse.
How accurate are the eclipse times?
Sun and Moon positions come from truncated VSOP87 and ELP-2000/82 theories, accurate to a few arcseconds. Contact times are typically within about a minute of published predictions, and totality durations within a few seconds. Mountains on the Moon's edge and your exact elevation can shift the moment of second and third contact slightly.
What is gamma?
Gamma is the distance of the Moon's shadow axis (for solar eclipses) or of the Moon's center (for lunar eclipses) from Earth's center at greatest eclipse, measured in Earth radii. A small gamma means a central, long eclipse; values near 1 mean the shadow only grazes Earth.
Is it safe to look at a solar eclipse?
Only with certified solar viewing glasses meeting ISO 12312-2 or a proper solar filter. Sunglasses are not safe. The only time you may look with the naked eye is during the brief total phase of a total solar eclipse, and you must put your protection back on as soon as the Sun starts to reappear. Lunar eclipses are completely safe to watch.
Why does a total lunar eclipse look red?
During totality the only sunlight reaching the Moon has passed through Earth's atmosphere, which scatters blue light and bends red light into the shadow. The Moon glows a copper or red color whose brightness depends on clouds and volcanic dust in Earth's atmosphere.
What is a hybrid solar eclipse?
A hybrid eclipse is total along part of its path and annular along the rest. It happens when the tip of the Moon's umbra just reaches Earth's surface near the middle of the path, where Earth bulges closest to the Moon, but falls short near the ends of the track.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.