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NIST Reports Lower Gravitational Constant After Decade-Long Study

4/17/2026

Summary

Story summary

Researchers at the National Institute of Standards and Technology (NIST) report a new value for the universal gravitational constant big G: 6.67387 × 10^-11 m^3/kg/s^2, about 0.0235% lower than the International Bureau of Weights and Measures result.
The measurement follows a decade-long effort using a torsion balance to quantify gravitational forces between masses.
The discrepancy highlights ongoing challenges in accurately determining big G and informs efforts to harmonize its value.

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Story summary

Researchers at the National Institute of Standards and Technology (NIST) report a new value for the universal gravitational constant big G: 6.67387 × 10^-11 m^3/kg/s^2, about 0.0235% lower than the International Bureau of Weights and Measures result.
The measurement follows a decade-long effort using a torsion balance to quantify gravitational forces between masses.
The discrepancy highlights ongoing challenges in accurately determining big G and informs efforts to harmonize its value.