Calculate how gravity warps time using general relativity — compare clocks near massive objects, black holes, neutron stars, and Earth.
One of the most remarkable predictions of Einstein's general relativity is that time runs slower in stronger gravitational fields. A clock on the surface of the Earth ticks slightly slower than one in orbit, and a clock near a black hole would almost stop from the perspective of a distant observer.
This effect, known as gravitational time dilation, is not merely theoretical—it has been measured with atomic clocks on aircraft, verified by GPS satellites that must correct for it daily, and observed in the spectra of white dwarf stars. Without accounting for gravitational time dilation, the GPS system would accumulate errors of about 10 kilometers per day.
This calculator uses the Schwarzschild metric from general relativity to compute the precise time dilation at any distance from a massive object. You can explore scenarios from the mild dilation of Earth's surface to the extreme warping near neutron stars and black holes, and see how everyday technology like GPS relies on this fundamental physics.
Gravitational time dilation connects abstract general relativity to real-world technology and cosmic phenomena. This calculator makes the math interactive, letting you explore scenarios from everyday GPS corrections to extreme black hole physics with visual comparisons and detailed tables.
This tool is designed for quick, accurate results without manual computation. Whether you are a student working through coursework, a professional verifying a result, or an educator preparing examples, accurate answers are always just a few keystrokes away.
Gravitational time dilation: t_near = t_far × √(1 − r_s/r), where r_s = 2GM/c² is the Schwarzschild radius, G is the gravitational constant, M is the mass, c is the speed of light, and r is the distance from the center.
Result: Time near Earth: 0.999999999303 years
On Earth's surface, 1 year is about 22 milliseconds shorter than 1 year measured far from any gravitational field, due to Earth's mass.
Use consistent units throughout your calculation and verify all assumptions before treating the output as final. For professional or academic work, document your input values and any conversion standards used so results can be reproduced. Apply this calculator as part of a broader workflow, especially when the result feeds into a larger model or report.
Most mistakes come from mixed units, rounding too early, or misread labels. Recheck each final value before use. Pay close attention to sign conventions — positive and negative inputs often produce very different results. When working with multiple related calculations, keep intermediate values available so you can trace discrepancies back to their source.
Enter the most precise values available. Use the worked example or presets to confirm the calculator behaves as expected before entering your real data. If a result seems unexpected, compare it against a manual estimate or a known reference case to catch input errors early.
The phenomenon where time passes more slowly in stronger gravitational fields, as predicted by Einstein's general relativity. Clocks closer to massive objects tick slower than those farther away. Understanding this concept helps you apply the calculator correctly and interpret the results with confidence.
Yes, multiple times. The Hafele-Keating experiment (1971) used atomic clocks on airplanes, and GPS satellites require daily corrections for both gravitational and velocity time dilation.
GPS satellite clocks tick about 45 microseconds faster per day than ground clocks due to weaker gravity. Without correction, GPS positions would drift by about 10 km per day.
At the Schwarzschild radius (event horizon of a black hole), the time dilation factor goes to zero—time appears to stop completely from an outside observer's perspective. Understanding this concept helps you apply the calculator correctly and interpret the results with confidence.
Yes. Gravitational time dilation comes from general relativity (gravity), while velocity time dilation comes from special relativity (motion). Both effects are real and can occur simultaneously.
In principle, spending time near a very massive object would cause you to age less than someone far away. This is forward time travel—you cannot go backward.