Group size estimator

How many trainers do I need to invite?

The Estimator is already "trainers of this attacker needed to finish inside the timer", so this page does not invent a number: it reads it off the boss's own ranked counter list for three realistic parties and re-simulates each of them at every level from 20 to 50.

Raid bossTierIVsWeatherFriendshipDodgingShadow attackersMega attackersLegendary attackers

Invite 2 to be safe — 2 if everyone is prepared

At level 40, a party of Mega Meganium's top six counters needs 1.08 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.45 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 5:01. No level in this range makes it soloable with a prepared party. A duo works from level 20.

Mega Meganium · Mega

grassfairy

Weak to

poisonflyingsteelfireice

Boss CP: 43,387
Boss HP: 9,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Mega Meganium at each attacker level
Attacker level	Six of the best counter	A prepared party	A mixed local group	Prepared solo time	Faints per timer
Level 20	2(1.44)	2(1.64)	3(2.20)	7:37	6.0
Level 25	2(1.25)	2(1.42)	2(1.86)	6:36	6.0
Level 30	2(1.01)	2(1.21)	2(1.64)	5:37	6.0
Level 35	1(0.94)	2(1.14)	2(1.55)	5:19	5.9
Level 40	1(0.92)	2(1.08)	2(1.45)	5:01	5.9
Level 45	1(0.88)	2(1.04)	2(1.39)	4:51	5.9
Level 50	1(0.84)	2(1.01)	2(1.35)	4:43	5.8

Whole trainers in bold, the raw estimator in brackets — 2.04 means two trainers is right on the line and three is comfortable.

Six of the best counter

Every trainer brings six copies of the single best counter — the theoretical floor.

1 trainer at level 40

Eternatus0.92

A prepared party

Each trainer brings the boss's top six counters, powered up and correctly TM'd.

2 trainers at level 40

Eternatus0.92
Zamazenta (Crowned Shield)1.06
Zacian (Crowned Sword)1.08
Roserade1.10
Naganadel1.14
Nihilego1.17

A mixed local group

Ranks 13-24: reasonable but unoptimised parties, which is what a public lobby usually is.

2 trainers at level 40

Vileplume1.34
Toxicroak1.37
Salamence1.39
Revavroom1.40
Reshiram1.45
Genesect (Douse)1.46

The party these numbers assume

1. Eternatus

Poison Jab + Sludge Bomb

2. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

3. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

4. Roserade

Poison Jab + Sludge Bomb

5. Naganadel

Poison Jab + Sludge Bomb

6. Nihilego

Poison Jab + Sludge Bomb

See the full ranked counter list for Mega Meganium · check a real lobby (win chance, who brings what) · make a share card of the top six

How this is worked out

The boss is ranked once at level 40 with rankCached (the same memoised call /raids makes), then the three bands — rank 1, ranks 1-6, ranks 13-24 — are re-simulated at each attacker level with an 8-run Monte Carlo each. Holding the party fixed and moving only its level is deliberate: it answers "what if my party were level 20" rather than "what would a level-20 player's completely different party be", and it is about ten times cheaper than re-ranking every attacker seven times. The Estimator itself is Pokebattler's definition, time to win including rejoin time divided by the raid timer.