It depends. Sometimes you get lucky and can carry a few kgs more than the allowed, sometimes they will only admit 0.5 kg more than your limit. Some rules of thumb, without being able to cite from anything, If you are on a business class ticket or have status with an airline, I would expect them to be more tolerant.

Most airlines in 2026 enforce weight limits with high precision, but the level of "mercy" you receive depends on the carrier's business model and the individual gate agent. For ultra-low-cost carriers (ULCCs) like Spirit, Ryanair, or IndiGo, there is almost zero tolerance; even being 0.5 kg (approx. 1 lb) over the limit can trigger a significant "excess baggage fee," which is often more expensive if paid at the counter than online. Full-service legacy carriers like Delta, Emirates, or Qantas may occasionally overlook a very minor excess (e.g., 0.5 to 1 kg) if the flight is not at maximum capacity and you are a polite, loyal customer with elite status. However, with the rising costs of fuel and the integration of highly accurate automated bag-drop scales, "slightly overweight" is increasingly a gamble you will lose. In 2026, new regulations in several regions mandate that airlines must allow you to move items into another bag or onto your person at the counter without penalty, but the weight limit itself remains a hard line for safety and revenue reasons. The best strategy is to weigh your bag at home and aim for 1 kg under the limit to account for scale variance.