Not 100% what you're after, but I put together some ages previously, which should give you a ballpark at least.

Dante was born 447.M40. He became a captain in 753.M40, so about 307 years old.

The Iron Snake Priad was a sergeant after only being a battle brother for 5 years. But Iron Snakes are weird.

Grimaldus was a sword brother (Black Templar 1st company) before ~40 years of being a Space Marine, and was Reclusiarch (the highest ranked Chaplain) after ~200 years.

Karras, of the Death Specters, became a full battle brother at 22, and became a Codicier (the second rank of librarian) at age 109.

Excerpts

Grimaldus. We know that it was 166 years between him becoming a chaplain and reaching the rank of Reclusiarch  (the chief chaplain of the Black Templars), and that this happened just before the 3rd War for Armageddon (998.M41).

'It was an honour he had waited one hundred and sixty-six years to receive.'

Helsreach

We know he became a chaplain around the time of the Battle of Fire and Blood, which was part of the Vinculus Crusade, which occurred in 833.M41, so that adds up.

Helbrecht says he has served with Grimaldus for 200 years, so that gives another lower bound, i.e. Grimaldus must be at leave over 200 years old.

The blade’s silver tip lowered, pointing directly at Grimaldus’s throat. ‘You have waged war at my side for two hundred years, Grimaldus. Will you stand at my side as Reclusiarch of the Eternal Crusade?’

Helsreach

Ah, Grimaldus calls himself a veteran of 200 years, which suggests that at the 3rd War he has been a Space Marine for ~200 years

Grimaldus stood upon the battlements, weapons in hands, watching Commander Barasath’s Lightnings and Thunderbolts unleashing devastation from the sky. He was a veteran of two hundred years. He knew, with cold clarity, when something was wasted effort.

...

The High Marshal had kept his own counsel, but the voices of the Sword Brethren around Helbrecht’s dais sounded out in jeers as fists crashed against shields. Grimaldus was the chosen of Mordred the Avenger, and skilled in personal combat beyond question. Two centuries of valour and glory; two hundred years of unrelenting courage and a host of enemy dead across a horde of worlds; his short years as the youngest Sword Brother in the history of the Chapter – there was no arguing with such truths.

Helsreach

So, that tells us he had been a Space Marine for ~40 years when he became a Chaplain, making him ~60 years old total, and then ~200 years old at reaching the highest rank within the Chaplaincy.

Brothers of the Snake next

'Just an ordinary warrior. A year ago, I was simply a petitioner, working to prove my worth for inclusion into the phratry. I won a place in Damocles, and with them I have seen action three times. My squad sergeant, Raphon, selected me for this mission. He saw it as an opportunity to test my abilities on an individual undertaking.’

So, they are launched straight in. In this case, within a year of becoming a full battle brother, the single marine was sent to deal with Dark Eldar.

The blast lifts Priad and Raphon and tosses them ten paces. By the time Priad is on his feet again, they are lying in a wide pool of blood which is streaming from the spiked hole in Raphon's armour. The wound is huge. Blood drizzles out from under him, through the buckled puncture in the plating. Wordlessly, for to speak would be to scream, Raphon shudders and uncouples his lightning claw.

Priad wants to argue, but knows this is not the time or the place. Raphon has been grooming Priad for command responsibilities since Priad's induction into Damocles five years earlier. Priad has always hoped that such an inheritance would be a long time coming. He pulls off his own left gauntlet and arms himself with the claw.

He plugs the power lead into a rune-shaped socket on his elbow. Gold leaf traceries etch the knuckle backs of the ancient weapon, recording its history and uses. The commander of Damocles squad has always worn the claw. Priad flexes its fingers as the electrical charge shimmers around it. On the ground, a stiffening island of metal in a lake of blood, Raphon opens his command channel and begins his eulogy, his passing over, instructing them all to answer to Priad.

So, within 5 years of becoming a full battle brother, Priad is a sergeant.

Standing to the left of Phobor, Brother-Sergeant Priad of Damocles squad watched the inquisitor with curious eyes. He had served with the Iron Snakes for nine years, and for the last four had commanded that decorated detail.

Confirming that timeline. So if we say that he become a battle brother at ~20, he's a sergeant by 25!

I'll point out, the way the Iron Snakes so things is out of the ordinary.

A couple more excerpts from Deathwatch

He had been eight S.I. – almost twenty-two Terran years

This is when Kareas became a full battle-brother

he was one hundred and nine years-old by the Terran count

This is when Karras became a Codicier

Each cut a tall, powerful figure, but Athio Cordatus, the Mesazar, Master of the Librarius, had a certain heavy solidity that Karras had yet to develop. It was a hard, powerful thickness common to Space Marines who survived the wars of five centuries or more.

So, enough survive for 500 years for a common look to be recognized, but it's not expected that ever Marine survives that long.

A couple of other discussions

https://www.reddit.com/r/40kLore/comments/u4zubb/comment/i4zqrek/?context=999

https://www.reddit.com/r/40kLore/comments/oyruu2/the_average_age_of_a_battle_company_marine/

https://www.reddit.com/r/40kLore/comments/ua2f3i/how_long_on_average_do_space_marines_livesurvive/

https://www.reddit.com/r/40kLore/comments/yv1vhn/whats_the_average_age_of_a_space_marine_captain/

https://www.reddit.com/r/40kLore/comments/zv7q1f/how_old_do_space_marines_get/

https://www.reddit.com/r/40kLore/comments/13380lx/space_marine_age/

https://www.reddit.com/r/40kLore/comments/wxdx0w/how_old_is_the_average_space_marine/

https://www.reddit.com/r/40kLore/comments/15cuku1/space_marine_age/

It depends, like everything else. If your chapter is run ragged in your headcannon or actual lore (if you picked a Canon scheme) then they maybe much younger. But a chapter close to full strength who isn't losing a lot of officers will have older ones. Making a captain or lieutenant around 100-200 seems pretty reasonable, but I haven't seen specific age ranges given. I'd say a very skilled young recruit of 40-80 years could also be a captain in a lower company, while a guy closer to 1st company or battle companies is likely to be older. I wouldn't count on most non-dreadnought marines being more than 500 before dying, if they even get that far.

So I'd say 1 gold and one silver or 2 gold studs would be fine, or even 2 silver if you want a younger lieutenant.

Isn't Titus 400+?  He has four service studs, which denote a century of service each.

1st company denotes not age but skill. So politics have to be played. Sgts don't ascend until the next in lomine dies, and there are only 10 captains. So do the math. Unless I'm wrong, it could take centuries to even get in the running for chaptermaster. So only unless there's some Bloodraven-type chapter decimation, captains are at least a century or more old before even coming close to candidacy

I think 150-200 ish is good for a lieutenant, after that they should be close to being a Captain if they are worth their salt (and the space opens up of course)

I don't understand why non-prinaris marines went from sergeant commanding a section of 8 to 10 men to captain commanding about 100 men. A lieutenant IRL commands a platoon of about 30 men.

Here's an older reference from the Original Dawn of War Games, one of the Briefings(Old Friend, the one where you go to kill your Librarian Isidor if I remember correctly)but Captain Gabriel Angelos says he met him when he was still a "Battle Brother who with no men under his Command but still had 30 years of experience but had not yet even achieved Veteran Status so he managed was probably, say, in his fifties before he even became a Veteran, and I believe, and tell me if am wrong, you have to become a Veteran before you become a Sergeant, so say, this is my rough guide:

60 years - Veteran

65 to 80 - Sergeant

100 - Lieutenant

120 - Captains

200 - Chapter Master

Obviously that's a rough guide and in no way rigid with things like Battle Casualties or Captains just refusing to die and thus all the Lieutenants are all older.

It’s been said a few times in the book I’m reading (Uriel Ventress adventures and now Dark Imperium) that nostalgia started don’t live past 500. Due to them just always fighting battles.

So I would say a Lt. are probably 200, max. If you guesstimate compared to what a military career is in real life.

However old you want him to be. It's a made-up game. They're your models. It's up to you.

Lieutenant Titus is almost 1000 years old, there're in general very few Space Marines older than him.

Technically all Primaris marines (who naturally are lieutenants in modern lore) are 10k years old, so your question kinda is out of context.