How to use the critical density of the universe calculator
Find the critical density of the universe from the Hubble constant and its equivalent in hydrogen atoms. Enter hubble constant in the field above; the critical density, hydrogen atoms per cubic metre are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “critical density universe”, “cosmic density”, “hydrogen atoms per cubic metre”, “calculate critical density of the universe”, “find critical density”.
Formula
Variables
- H0 — Hubble constant (km/s/Mpc)
Worked example
With hubble constant = 70 km/s/Mpc, the calculator gives critical density ≈ 9.2037 × 10⁻²⁷ kg/m³; hydrogen atoms per cubic metre ≈ 5.502583 atoms/m³.
Frequently asked questions
What is the critical density of the universe calculator used for?
Find the critical density of the universe from the Hubble constant and its equivalent in hydrogen atoms. It helps with questions such as “critical density universe”, “cosmic density”, “hydrogen atoms per cubic metre”.
What is the formula for the critical density of the universe calculation?
Critical density (kg/m³) = 3 × (H0 × 1000 / 3.0857e22)^2 / (8 × π × GCONST). Hydrogen atoms per cubic metre (atoms/m³) = [Critical density] / MP. Here H0 is hubble constant (km/s/Mpc).
What inputs do I need for the critical density of the universe calculator?
You need hubble constant in km/s/Mpc. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the critical density of the universe calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the critical density of the universe result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.