Tool 002 · the climb
K = 0.728
Humanity's position on the Kardashev scale, computed from the latest real world energy figure, with the formula and every assumption on the table.
The number
19.02 terawatts, continuously
World commercial primary energy in 2025 was just over 600 EJ (600.3 EJ per the OWID sum of the Energy Institute Statistical Review 2026 series, up 1.7% on 2024). Spread over the year that is an average power draw of 19.02 TW, K = 0.728. Including traditional biomass (~40 EJ) it is K = 0.731; the log scale makes the methodology choice worth only 0.003.
The climb so far
Every energy empire fits in 0.12 K
Biomass-inclusive series: Smil (2017) via OWID before 1965, the BP/EI annual series after. Standard Oil, Insull, Aramco, and Tesla all happened between the first bar and the last. The titans study tells that story.
The calculator
When does Type I arrive?
Pure arithmetic from the number above: pick a sustained global energy-consumption growth rate and see how long 526× takes.
Type I in 316 years · around 2342
- Energy-only method, via the interpolation commonly attributed to Sagan. Honest provenance note: Gray (2020, The Astronomical Journal) shows no explicit equation appears in Sagan's Cosmic Connection; Sagan interpolated in prose (classing 1973 Earth as Type 0.7), and the explicit formula appears later. We cite the interpolation, not "Sagan's equation."
- Commercial primary energy, gross consumption, per the Energy Institute definition. Traditional biomass (~40 EJ) excluded from the headline; including it gives K = 0.731.
- Seconds per year: 31,556,952 (mean Gregorian year).
- Constant compound growth is an assumption, not a forecast. 2025's actual growth was 1.7%.
- Cross-check: kardashev1.com states K = 0.730 ± 0.02 on the same method; our commercial-only 0.728 sits inside their band, and a biomass-inclusive computation lands on their 0.730 exactly.