The **Kardashev scale** is a method of measuring a civilization's level of technological advancement, based on the total energy usage of a civilization. The scale is exponential and hypothetical and regards energy consumption on a cosmic scale. It was proposed in 1964 by Nikolai Kardashev and modified in 1973 by Carl Sagan in his book *The Cosmic Connection*, which is the scale we use.

Carl Sagan defined intermediate values (not considered in Kardashev's original scale) by interpolating and extrapolating the values given for types I (10^{16} W), II (10^{26} W) and III (10^{36} W), which would produce the formula K=(logP-6)/10 where *K* is a civilization's Kardashev rating and *P* is the power it consumes, in watts. Using this extrapolation, an early Type 0 civilization, not defined by Kardashev, would consume about 1 MW (10^{6} W) of power.

A toe is a "tonne of oil equivalent" which is 42 gigajoules and 1 Mtoe = 11.63 TWh (terawatts per hour).

Humanity's civilization type as of 1973 was about 0.7, using 7 101.3 Mtoe = 82 588 TWh arriving at an average hourly power consumption of 10 terawatts (TW) .

Total Mtoe is primary energy found in nature and not yet engineered. It is all non-renewable and renewable, comprised of oil, coal, gas, minerals for nuclear power, solar, wind, hydro, biomass and geothermal. __This total is used to calculate the K-rating.__

In 2018, the total world energy consumption was 14 421 Mtoe = 167 716 TWh for the year . The calculation is 167716 / 365 / 24 to get an average hourly power consumption of 19.14 TW. The final calculation is (log 19 140 000 000 000 - 6) / 10 to make **0.73** on Sagan's extended Kardashev scale.

2018 data sources from International Energy Agency (source 1 and source 2) and original source.

2019 data is 583.9 exajoules = 162194.44 TWh.

2020 data is 556.63 exajoules = 154619.44 TWh.

2021 data suggests 17.7 TW. The final calculation is (log 17 700 000 000 000 - 6) / 10 to make **0.72**. This drop was due to the COVID-19 pandemic.

2022 data suggests a 6% increase from the previous year. The final calculation is (log 18 760 000 000 000 - 6) / 10 to make **0.727** which takes us back to **0.73**.

2023 data saw a 1% increase, taking it to around 3% above the 2019 pre-COVID level. Continued recovery from the COVID-19 pandemic, legacy supply chain issues, along with conflict in Ukraine, continued to impact the global energy sector. We are still 0.73.

EIA projects nearly 50% increase in world energy usage by 2050. This is about 29 TW which approaches 0.75 on the Kardashev scale in 2050.

This paper suggests that if nuclear fusion is achieved, which is an energy and industrial revolution, we are expected to reach Type 0.77 by the end of the twenty-first century. However, if the current energy structure does not change, and the human civilization follows its current trend, we will only reach Type 0.75 by the end of the twenty-first century.

Freeman Dyson calculated in 1959 that if mankind's Malthusian (exponential) growth rate in energy consumption were to continue, the human race would reach a crisis point within the next two to three millennia. At this point, all the non-renewable sources would be exhausted, and even renewable sources exploited on a planet-wide scale would be unable to cope with further demand. To provide for future growth, the human race will need to capture much more of the Sun's light with a Dyson sphere.

Michio Kaku suggested that if humans increase their energy consumption at an average rate of 3% each year, they may attain Type I status in 100–200 years, Type II status in a few thousand years, and Type III status in 100,000 to a million years. Kaku and others proposed extensions of the scale for Type IV onwards. This varies between superclusters and the universe for IV, various levels of the multiverse for V, and godly universe-creators and matter manipulators for VI. We try to define this more carefully based on the infinity map.

An entropy limiting factor should also be considered in an adjustment to the scale. An advanced civilization will be able to perform vastly more tasks with less energy than we use today, and far less wastage due to friction. This was evident from 1920 to 1970 where the K-rating increased more rapidly than from 1970 onwards where we became more energy-efficient. One example is the transistor and die-shrink scaling. We are able to perform magnitudes more compute with magnitudes less energy usage. Another example is the electric car, which can go a lot faster than cars with combustion engines, using less energy. Energy efficiency is also important for transistor cooling and reducing die-cast sizes.

Another consideration for energy efficiency is Landauer's principle, pertaining to the lower theoretical limit of energy consumption of computation which is approximately 0.018 eV (2.9×10^{−21} J). Modern computers use about a billion times as much energy per operation, which means they can get more efficient by 9 orders of magnitude using nanomechanical computronium. In the far future a Matrioshka brain could get even more efficient using a Carnot engine. This is a setback and even a criticism of the Kardashev scale, and so to truly scale exponentially, one would have to consider a much higher multiplicative number of colonies across vast distances.

A pessimistic estimate from Xenology is as follows:

If the historical 3% growth rate is maintained, then by the year 2300 mankind's energy budget will be up to 2 x 10^{17} W, which is also the total power received from from the Sun to Earth. We will then face the most critical "energy crisis" in the history of Earth. All forms of energy (electrical, thermal, mechanical, nuclear) ultimately returns to the biosphere as *heat*, causing the global temperature to rise and the precarious energy balance of the biosphere begins to suffer irreversible damage. By the time artificial energy production equals total solar influx, the planet will have suffered serious ecological damage. Earth would no longer be inhabitable by humans, our lush green world converted into a stewing, steamy hellhole like Venus.

A safe level is likely the photosynthetic energy limit, or the total solar energy used by green plants worldwide which is about 4 x 10^{13} W. Using 1% of the total solar influx (10^{15} W) would be a critical limit, sufficient to melt the polar icecaps and thoroughly disrupt the entire ecology.

*"We estimate, therefore, that the maximum upper limit of artificial energy generation for any Type I planetary culture limited to a single world in our galaxy is roughly 10 ^{15} watts".*