Ryanair: standard limit is 44 lb per bag — overweight or oversized bags cost extra on top of the regular baggage fee.
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Over the 20kg (44lb) allowance: charged per kilo, often €10-12/kg if paid at the gate — one of the steepest overage rates of any major carrier.
Over 32kg (70lb): not accepted at all by most ground handlers, for baggage-handling safety reasons.
Oversized or odd-shaped items (sports equipment, musical instruments) need a separate special-item booking, not just an oversize fee.
Pre-booking extra weight online is dramatically cheaper than paying the per-kilo gate rate — do it before you travel, not at check-in.