Khuram Butt, 27, Rachid Redouane, 30, and Youssef Zaghba, 22, mowed down pedestrians on the bridge before stabbing random members of the public around Borough Market.
They were armed with ceramic knives and had fake suicide belts strapped around their waists during the marauding attack on the evening of June 3 2017.
The rampage was halted after less than 10 minutes when the attackers confronted three armed police in Stoney Street.
The Old Bailey heard that the officers shouting warnings and opened fire as Butt, Redouane and Zaghba came at them.
In the hail of bullets, a man in the nearby Wheatsheaf pub was hit by a stray round but survived.
Fearing Butt and Redouane could still detonate explosive devices as they lay injured, the police officers shot at them again, jurors were told.
A bomb disposal expert told the court he only realised the suicide belts were fake after he cut them off the dead bodies and held them up.
Jurors deliberated for three-and-a-half hours to conclude that all three attackers were lawfully killed by police after they "ignored clear warning shouts".
Chief coroner Mark Lucraft QC had directed them that was the only "safe" conclusion in the circumstances.
He praised the actions of the armed officers and said nothing less than "lethal force" had been appropriate.
He told jurors: "You may well agree they acted with courage and they only used such force as was necessary."
During the inquest, jurors visited the spot in Stoney Street where Butt, Redouane and Zaghba died and heard dramatic accounts of the final moments.
Pc Sam Balfour, 25, and Pc Bartek Tchorzewski, 36, were among unarmed officers who tracked the attackers through Borough Market.
In an interview coinciding with the conclusion of the inquest, Pc Tchorzewski said: "We were just thinking about stopping them. Assume the worst and you try to think what you may encounter and what we will do.
"But to be honest nothing can prepare you for that. No briefings."
Pc Balfour said: "I was quite aware walking down they could spring out at us at any second."
When armed police arrived on the scene, Pc Balfour feared he was in the line of fire and might get shot himself.
He said: "We started to shout, 'That's them, that's them', pointing out those terrorists, 'Shoot them'."
An armed officer identified only as BX46 told jurors he shouted words to the effect of "armed police, stand still, drop the knife", believing he was in immediate danger as Butt came at him.
He said: "I believe his intention was to use the knife and stab me, kill me and get hold of my weapons.
"At this point I was aware that around his torso he was wearing an improvised explosive device.
"I already knew he had a knife and he was a threat to my life but now he was an even bigger threat, even with one or two metres a detonation would be fatal to colleagues, members of the public, anyone in the location.
"So I aimed my rifle towards the male and I was moving back quickly and I moved the fire selector lever to fire and I pulled the trigger."
His colleague BX44 also shot at Butt but had break away to shoot at Redouane as he bore down on another colleague, BX45.
He said: "I carried on firing until I had to deal with the third threat of Youssef Zaghba who was on top of me.
"I was backing away trying to create a reactionary gap when I fired and fell backwards, and as I fell backwards I fired and from the floor I fired through my legs up to his chest. I thought he was about to kill me."
Pc Iian Rae said he went to handcuff Redouane as he moved on the ground while his colleague Pc Tim Andrews handcuffed injured Butt.
Pc Rae said: "His arms and legs were moving and I knew he had an IED (improvised explosive device) strapped to him.
"I did not know they were fake. I had to make a split-second decision - if I don't go and do something there is going to be a lot more lives lost.
"I had to handcuff him and stop him from detonating that device, if they were real or not.
"As I went over there to handcuff that person I was shouted at by firearms officers. They have told me to get out and I have taken their advice and I ran."
The firearms officers then used "lethal force" to avert the danger that the terrorists would detonate explosive devices, jurors heard.
Pc Rae, 51, who was called on to protect the public in the wake of the 7/7 London bombings in 2005, was one of a number of officers recognised for their bravery.
He said police teamwork on the night of the London Bridge attack was "magnificent".
A separate inquest concluded victims Xavier Thomas, 45, Chrissy Archibald, 30, Sara Zelenak, 21, James McMullan, 32, Kirsty Boden, 28, Alexandre Pigeard, 26, Sebastien Belanger, 36, and Ignacio Echeverria, 39, were unlawfully killed.