3D simulation shows the speed difference between Usain Bolt, the world's fastest greyhound and a cheetah

A 3D simulation has compared Usain Bolt's 100-metre world record speed with that of the world's fastest greyhound and cheetah.

Bolt is celebrating his 40th birthday on Friday (August 21), having long since retired from competitive athletics.

He hung up the competitive running spikes for the last time after the 2017 World Athletics Championships, where he finished in third place in his final 100m race.

Eight years earlier was the scene of his iconic world record time of 9.58 seconds, set in Berlin.

It is a mark that has never come close to being beaten, with the current world-leading time of 9.79 seconds set by Noah Lyles at the USATF National Championships in July.

READ MORE: Noah Lyles is the new fastest man on the planet this year after sensational finish to 100m race

With technological advancements happening all the time in athletics, it remains to be seen as to whether the next generation of sprinters can beat Bolt's record.

Australian star Gout Gout, who has a 100m personal best of 10.00 at the age of 18, is perhaps even better suited to the 200m event, which Bolt also holds a world record in.

READ MORE: Gout Gout's second world record in rare race not recognised because of little-known rule

Usain Bolt vs greyhound vs cheetah simulated

As things stand, with no human able to match Bolt's sprint speed, it's down to animals to rival him.

YouTube channel MotionAthlete specialises in simulating Bolt against some of the world's fastest animals, with a greyhound and cheetah among them.

Back in 2024, the channel pitted both animals in a straight 100m race against Bolt - and to put things simply, you wouldn't want either the greyhound or the cheetah to be chasing you down.

The cheetah finished the 100m sprint in a time of 4.74 seconds, with the greyhound managing it in 5.82 seconds.

You can see the full race, which starts at 2:46, below:

MotionAthlete calculated the top speeds of all three competitors to judge their times over 100 metres - though, of course, Bolt's already established best time of 9.58 seconds was used.

The greyhound has a top speed of 77km/h, while the cheetah comes in at a staggering 120km/h.

It takes the greyhound 60 metres to reach top speed, with the cheetah taking only 50 metres.

In his retirement, Bolt has stopped running and revealed in an interview with The Telegraph in September that he very much leads a normal life nowadays - one which is far removed from his time in sprinting.

"Normally, I wake up just in time to see the kids off to school, and then it just depends on what I have to do," the Jamaican explained.

"If I have nothing to do, I just chill out. I might work out sometimes if I'm in a good mood. I just watch some series and chill until the kids come home.

"I spend some time with them, hang out, until they start annoying me. Then I leave. Afterwards, I just stay at home and watch movies, or I'm into Lego now. So I do Lego."