Diablo IV

This one is quite a grind, so buckle up!

An important note I wanted to preface this with: Paragon experience is now account-wide. Seasonal paragon experience will not carry over to new seasons, but WILL roll over into the Eternal realm when the season ends and add up cumulatively in Eternal over the course of the seasons that you play, so you can grind this out over multiple seasons and do not need to strictly play Eternal for fear of losing all of your progress on reset.

Further below is a rough breakdown of the experience required for this. But first, a few tips on how to grind this out.

How to Grind:

As of the writing of this guide, running Pits offers the highest experience per hour by a good margin. You should try to shoot for whatever Pit level you or your group can fully clear in around 90-120 seconds, regardless of the level - this applies at all levels, but becomes even more important in higher pits, as the increased experience lowers greatly as you go higher. For instance, the difference in the experience you receive for completing the dungeon between pit 65 and pit 70 is about 5.24% - already quite a small difference - but the difference between pit 95 and pit 100 is only about 3.24%. Even less of a return for higher levels. This applies to the monsters in the pit as well.

Let's check some numbers to demonstrate - for practicality, I'll only use completion experience for these numbers as that's where the majority of the experience comes from.

Pit 100 grants 7,950,000 on completion. If you can run a level 100 pit every 2 minutes exactly (including looting, spending obols, resetting, whatever), you can do 30 runs per hour for a total of 238,500,000 experience per hour.

Pit 95 grants 7,700,000 on completion. If you can do a pit 95 fifteen seconds faster than a pit 100 (1:45), you'll be able to fit in an extra 4 runs (about 4.25) for a total of 261,800,000 experience per hour, a 9% increase in experience. Even if you could only fit in one extra run per hour (31 instead of 34), the experience would still be slightly higher at 238,700,000 per hour.

Now let's crank it all the way up and say you're running a hyper meta build and can run pit 150 in only about 3 minutes per run. Pit 150 grants a nice 10,950,000 upon completion, but adding that extra minute per run means that you can only run about 20 pits per hour, so your total experience is only 219,000,000 per hour. You'd be gaining experience faster doing 2 minute 100's.

All of the above numbers are realistically low as they only account for dungeon completion experience and not mob experience, but completion experience is where the majority of your run experience comes from and scales similarly to mob experience, so the ratios remain very similar.

TL/DR: Unless there are only a few seconds of difference, do the fastest pits you can do regardless of the pit level for maximum experience per hour. But most importantly, don't burn yourself out trying to be as efficient as possible if that's not for you - just have fun!

Consumables:

Although it doesn’t count for the majority of your experience in Pits, mob experience does definitely add up over time, so to get the most of it, you can run several items to increase your experience gained. These items only affect monster experience and have no effect on the experience you receive when completing the dungeon.

1. Elixirs - There are various types of elixirs that grant you different boons such as extra health, crit chance, attack speed, resistance to an element, etc, but what's most important to us here is that all of them give you increased experience as well. Basic elixirs grant you a 5% experience bonus and advanced elixirs grant you an 8% bonus. They last 30 minutes and you can only have one active at a time. They can be found in the world or crafted at an alchemist.

2. Incense - In a nutshell, incense serve the same purpose as elixirs but apply their buffs to all nearby players in addition to yourself. There are 3 different "types" (levels) of incense and you can activate one of each type at a time. Having an incense active gives you a 5% experience buff that stacks with other items, but you can only gain the experience bonus of one incense no matter how many you have affecting you. Incense can also be crafted at an alchemist. They last 20 minutes.

3. Opals - These were introduced in season 6 as part of the seasonal mechanic and are obtainable from Realmwalkers and also from world bosses. They grant various buffs which are quite powerful (making enemies drop extra runes, boss materials, gold, etc) and also grant an extra 15% experience. They last 30 minutes.

4. Experience Wells - Found only in Nightmare Dungeons, these grant you a 15% experience buff for a full hour.

It's debated whether or not spending time farming experience wells and opals before a grinding session is worth it overall instead of just investing the time grinding instead, it's up to you to decide what works for you. You can also outright purchase opals/elixirs/incense from other players as well.

The Numbers:

Now then, concerning the actual experience numbers.

Paragon experience starts out modestly, with 600k experience required to reach paragon level 1 after your character reaches level 60. Starting from paragon 3, the experience requirement keeps increasing every level all the way up to 300. This doesn't sound too bad at first glance, but the growth is exponential and, much like similar ARPGs, the hardest levels to grind are toward the end.

Let's take a look at a few numbers.

The total experience required for paragon 300 is 24,778,251,301.

When you reach paragon 100, you will have accumulated a total of 119,104,713 experience, putting you 0.48% of the way there.

At paragon 200, you will have 859,486,584 experience, and will be 3.47% finished with the job.

Paragon 250 = 3.1b = ~12.5%

Paragon 270 = 6.8b = ~27.5%

Paragon 280 = 10.3b = ~41.6%

Paragon 290 = 15.7b = ~63.3%

Paragon 300 = 24.78b = 100%

As you can see, more than a third of the experience required (~36.7%) is in the last 10 paragon levels. More than half of the experience required (~58.4%) is in the last 20. The halfway point of the journey is about halfway through P284.

Good luck - and most importantly, have fun!