Densidade crítica Universo
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The critical density of the universe (ρc) calculator is a cosmological tool to estimate the density required to balance the universe's expansion. The formula ρc = 3H²/(8πG) links critical density to the Hubble constant (H) and gravitational constant (G). This calculation helps determine whether the universe is open, closed, or flat by comparing actual density to critical density.
To use the calculator, input the Hubble constant (H), representing the universe's expansion rate. The result is the critical density in kg/m³, using standard values for G. This metric is vital for studying cosmic evolution and dark energy density.
Cautions: Accuracy depends on the precision of H's value. The Hubble constant remains a topic of scientific debate, with varying estimates. Additionally, the formula assumes a homogeneous and isotropic universe, which may not account for complex local realities.
Frequently asked questions
What is the Hubble constant?
The Hubble constant measures the universe's expansion rate, expressed in km/s/Mpc. Its value directly affects the calculated critical density.
Why is critical density important?
It defines the universe's geometry: higher density leads to a closed universe; lower, to an open one; equal density results in a flat universe.
How does dark energy affect this calculation?
Dark energy contributes to the universe's total density, but this calculator uses the theoretical critical density formula without additional terms like dark energy.
Do I need to convert units before using the calculator?
Yes, ensure the Hubble constant is in km/s/Mpc and use the standard gravitational constant (G = 6.674×10⁻¹¹ m³/kg·s²).