How to compare power consumption of 433 MHz and 2.4 GHz?

Question

When i google for power consumption 433mhz 2,4ghz and similar most results tell me that 433MHz consumes less power... but when I look at specifications of explicit chips/modules I can't seem to find a 433MHz module that use less power than the 2,4GHZ module.. 
 For example those two nordic chips: 
 www.nordicsemi.com/.../nRF51822 
 6.3mA - TX at -4dBm 
 www.nordicsemi.com/.../nRF9E5 
 9mA Radio TX at -10dBm 
 The SUB-1-GHz chip seems (at least it seems to me) to loose the duel. Less signal, more power use.
Where's my mistake? 
 As I don't need a long range nor much throughput, power consumption is all that matters to me. The less the better. a few years out of a CR2032 would be ideal.. (Every 5 or so seconds a measurement via SPI from a sensor, and then send the two 24bit values via bluetooth)

mnhs · Accepted Answer

One of the advantages of 433 Mhz is the free space path loss. It is about 15dB less with 433 Mhz when compared to 2450 Mhz. Thus, you theoretically achieve about 5 times more range with same output power and receiver sensitivity (source - playing with this calculator www.qsl.net/.../jsffield.htm ). But as written in your question, the range is not your priority. 
 If your only priority is the battery life, I would recommend to go for nRF51xxx and ANT-like protocol or advertise the data as a Bluetooth beacon (send non-connectable advertising packets). These types of communication do not need any communication between transmitter and receiver, I would call them "passive" protocols. Also care about the battery you use. You shouldn't use standard cheap CR2032, but some kind of special one with low self-discharge current. Then you should be able to achieve several years of battery life. 
 Note: Please be aware that this approach will offer you extended battery life, but it is quite dangerous for critical applications. The data cannot be properly encrypted without two-way communication and so the communication can be sniffed and also hacked quite easily.

How to compare power consumption of 433 MHz and 2.4 GHz?

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