Life span of Brahma

There are several Brahmas, each of them lives for a span known as 100 Brahma years.
1 Brahma year = 100 Kalpas = 8640,000,000,00 human years.
1 Kalpa = 14 Manavantaras = 8640,000,000 human years.
1 Kalpa = 2000 times the span of Kali Yuga (432000 years).
= 1000 times the span of Dwapara Yuga (864000 years).
= 500 times the span of Treta Yuga (1296000 years).
= 250 times the span of Satya Yuga (1728000 years).