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 4 to be safe — 4 if everyone is prepared

At level 40, a party of Mega Rayquaza's top six counters needs 3.04 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 3.85 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 13:59. No level in this range makes it soloable with a prepared party.

Mega Rayquaza · Super Mega

dragonflying

Weak to

icerockdragonfairy

Boss CP: 92,970
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 Rayquaza 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	4(3.77)	6(5.21)	7(6.32)	24:00	6.0
Level 25	4(3.17)	5(4.43)	6(5.11)	20:24	6.0
Level 30	3(2.81)	4(3.67)	5(4.34)	16:54	6.0
Level 35	3(2.71)	4(3.35)	5(4.07)	15:25	6.0
Level 40	3(2.59)	4(3.04)	4(3.85)	13:59	6.0
Level 45	3(2.12)	3(2.82)	4(3.67)	12:59	6.0
Level 50	2(1.94)	3(2.70)	4(3.55)	12:25	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

Kyurem (White)2.59

A prepared party

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

4 trainers at level 40

Kyurem (White)2.59
Eternatus2.81
Mamoswine3.00
Glaceon3.22
Cetitan3.23
Weavile3.38

A mixed local group

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

4 trainers at level 40

Zamazenta (Crowned Shield)3.66
Galarian Darmanitan (Standard)3.65
Avalugg3.65
Articuno3.77
Zacian (Crowned Sword)3.81
Beartic3.84

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Eternatus

Dragon Tail + Dynamax Cannon

3. Mamoswine

Powder Snow + Avalanche

4. Glaceon

Frost Breath + Avalanche

5. Cetitan

Ice Shard + Avalanche

6. Weavile

Ice Shard + Triple Axel

See the full ranked counter list for Mega Rayquaza · 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.