How Many Trainers Does a Raid Need? Estimating Group Size

Every raid boss has a fixed amount of HP that depends only on its tier, and every raid has a fixed timer. Divide one by the other and you get the damage per second the whole lobby must deal. Divide that by what one trainer deals and you have the group size. Nothing else decides whether a raid is possible.

That is why "you need five people for a legendary" is a poor rule. Five trainers with their six highest-CP Pokemon can fail a raid that two trainers with the right counters finish with time to spare. The number that matters is not how many people are in the lobby but how much damage each of them brings.

The one formula

Trainers needed = boss HP ÷ (your team's DPS × timer × uptime), rounded up.

Uptime is the share of the timer you actually spend attacking. You lose seconds to the opening animation, to Pokemon fainting, to the boss's charged attacks and to rejoining when your party is wiped. The estimates on this site's raid boss pages use 85% for a lobby of six strong counters each and 45% for a mixed lobby where some teams are under-levelled and people rejoin. Those two figures are assumptions, not game constants — they are there so the result is a range you can plan with instead of a single optimistic number.

For scale: on this site's rankings, a level-40 top counter hitting for super effective damage deals roughly 25 to 35 DPS, and a counter exploiting a double weakness can pass 40. A level-30 Pokemon of the right type deals noticeably less, and a high-CP Pokemon of the wrong type can deal a third of that.

Read the table with that in mind. A 1-star boss is beaten by anything. A 3-star boss needs 20 DPS, which one good team delivers. A Mega needs 30, which is right at the edge of one excellent team and comfortable for two. A 5-star needs 50, which no single trainer reaches — that tier is where group size becomes a real question.

Mega Legendary and Primal bosses have far more HP than a regular Mega. The figure the community works with, and the one this site's estimator uses, is 22,500 HP on the same 300-second timer, which is 75 DPS for the lobby — half as much again as a regular 5-star.

A 5-star boss with ordinary counters

Your six counters average 30 DPS against the boss. With strong teams all round, each trainer deals 30 × 300 × 0.85 = 7,650 damage. The boss has 15,000 HP, and 15,000 ÷ 7,650 = 1.96, so two trainers can do it — with almost nothing to spare.

Now assume a realistic public lobby: 30 × 300 × 0.45 = 4,050 damage each, and 15,000 ÷ 4,050 = 3.7, so four trainers. That gap between two and four is the whole reason lobby advice sounds contradictory: both numbers are correct, for different lobbies.

The same tier with a double weakness

Against a boss whose two types share a weakness, the right attackers hit for 2.56× instead of 1.6× and an average of 40 DPS is realistic. Strong lobby: 40 × 300 × 0.85 = 10,200 each, 15,000 ÷ 10,200 = 1.47, still two trainers but now with a third of the timer left. Mixed lobby: 40 × 300 × 0.45 = 5,400, 15,000 ÷ 5,400 = 2.8, so three.

A 3-star solo

Six counters averaging 25 DPS: 25 × 180 × 0.85 = 3,825 damage against 3,600 HP. 3,600 ÷ 3,825 = 0.94, so one trainer finishes with seconds left. Drop to a team averaging 18 DPS and the same sum gives 2,754 damage — a loss. This is the tier where powering up six Pokemon of one type pays for itself, because it turns a raid you need a friend for into one you can do alone on the way to work.

Things that add damage

• Weather. Moves of a weather-boosted type deal 20% more damage in raids. If your counters' type is boosted, a borderline duo becomes a safe one. The boss's own boosted moves hit harder too, and the catch afterwards is level 25 instead of 20.
• Friendship. Raiding with friends adds an attack bonus: 3% for Good Friends, 5% for Great, 7% for Ultra and 10% for Best Friends, plus extra Premier Balls at the higher levels.
• A Mega on the field. While a Mega Evolved Pokemon is out, every other trainer's attacks deal 10% more damage, and 30% more for moves that share a type with the Mega. One trainer leading with the right Mega is worth more than their own damage.
• Party Power. In a Party Play group (up to four trainers, in person, level 15 or higher), Party Power doubles the damage of your next charged attack, and it charges faster the more members there are.

Things that take damage away

• Remote raiders. Niantic states that remote trainers' Pokemon have lower attack power. Count a remote-heavy lobby as slightly weaker than its head count.
• Recommended parties. The game's suggested team favours survival over damage and regularly includes Pokemon the boss resists. Build a battle party for the boss from its counter list before the lobby timer starts, not during it.
• The boss's moveset. A boss carrying a move that is super effective against your counters wipes them faster, which costs uptime. If your whole team shares a weakness, the 85% assumption is too kind.

None of these change the formula. They change the DPS and the uptime you feed into it, which is why two lobbies of the same size get different results. The way to read a counter list properly is covered in how to read a raid counters list.

Shadow Raids

In 3-star and 5-star Shadow Raids the boss becomes enraged at 60% HP, dealing and resisting more damage, and calms down again at 15%. Purified Gems subdue it: it takes eight in total and one trainer can use at most five, so fully subduing an enraged boss needs at least two people even if one of them could out-damage it alone. Four Shadow Shards make one Gem. Shadow Raids have been open to remote raiders since May 2025.

Super Mega Raids

Introduced in February 2026, these are the one raid type with an official recommendation: at least seven other trainers, so eight or more. The boss raises shields that only the charged attack of a Mega Evolved Pokemon can break, one shield per trainer, and Primal forms do not count for this. The game will not let you press Ready without a Mega in your party. Here the limiting factor is how many people bring a Mega, not raw DPS.

Elite Raids

Elite Raids are in-person only: the egg sits on the gym for 24 hours and the raid itself is open for a 30-minute window. Remote passes do not work, so the lobby is whoever turns up. Arrange it beforehand.

A lobby holds up to 20 trainers and counts down from 120 seconds. That countdown is when the decision is made, so have the number in your head before you join.

• Know your own DPS band. If your counters for this boss are level 40 and super effective, you are a "strong" trainer in the sums above. If they are level 30 or you are filling gaps with whatever is left, count yourself as half of one.
• Count people, then discount. In a public lobby assume the mixed-lobby figure. If the page says two to four, four is the number at which you stay; at two or three, stay only if you know the others.
• A failed attempt is not a lost pass. The pass belongs to that raid, not to one try: if the lobby falls short you can go back in with the same pass while the raid is still on the gym. Use the first attempt to see how far a group gets, then decide whether one more person would close the gap.
• Raid Hours fix the problem for you. During a Raid Hour or Raid Day every gym has the same boss and lobbies fill without organising. The event calendar lists them. If you play somewhere quiet, those are the days to spend passes on 5-star bosses.
• Remote invites cut both ways. You can join 10 remote raids a day, and a host can invite friends from anywhere — useful when the local lobby is one person short, as long as you remember the remote damage penalty.

The long-term fix is cheaper than it sounds: one team of six good counters per common weakness removes most of the uncertainty. The best attackers by type pages rank them, and the Stardust guide covers the order to build them in.