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 5 to be safe — 4 if everyone is prepared

At level 40, a party of Mega Meganium's top six counters needs 3.14 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.17 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 14:27. No level in this range makes it soloable with a prepared party.

Mega Meganium · Super Mega

grassfairy

Weak to

poisonflyingsteelfireice

Boss CP: 72,312
Boss HP: 25,000
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	5(4.38)	6(5.14)	7(6.47)	23:38	6.0
Level 25	4(3.52)	5(4.43)	6(5.43)	20:24	6.0
Level 30	3(2.88)	4(3.53)	5(4.77)	16:14	6.0
Level 35	3(2.74)	4(3.32)	5(4.42)	15:16	6.0
Level 40	3(2.62)	4(3.14)	5(4.17)	14:27	6.0
Level 45	3(2.53)	3(2.99)	4(3.99)	13:46	6.0
Level 50	3(2.44)	3(2.92)	4(3.83)	13:26	6.0

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.

3 trainers at level 40

Eternatus2.62

A prepared party

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

4 trainers at level 40

Eternatus2.62
Zamazenta (Crowned Shield)3.05
Zacian (Crowned Sword)3.09
Roserade3.17
Necrozma (Dusk Mane)3.41
Naganadel3.51

A mixed local group

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

5 trainers at level 40

Salamence3.97
Overqwil4.02
Reshiram4.05
Moltres4.12
Genesect (Douse)4.12
Muk4.18

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. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

6. Naganadel

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.