Enter what the recipe says for a conventional oven - get the air fryer temperature and time instantly.
For fresh food, the adjustment is consistently the same across air fryer guidance - reduce the oven temperature by 25°F (about 15°C) and cut the cooking time by roughly 20%, since an air fryer's rapid, concentrated air circulation cooks faster and browns the outside sooner than a conventional oven would. That specific figure, 400°F for 30 minutes becoming 375°F for about 24 minutes, is the exact example cited consistently across independent air fryer references, and matches what this calculator gives.
Frozen food gets a different, separately-cited rule: keep the oven temperature as written, and cut the time by roughly 30-50% instead, since frozen food needs that higher heat to crisp up properly rather than steam.
Treat this as a strong starting point, not a guarantee - check food a few minutes before the adjusted time on a first attempt, the same advice every source on this topic repeats.
Does this work for a Ninja, Cosori, or Instant Vortex? Yes - and here's the honest reason why there aren't separate brand modes on this calculator: no major brand publishes a different conversion rule. The 25\u00b0F/20% adjustment reflects the physics of rapid air circulation, which every basket-style air fryer shares. What actually differs between brands and models is wattage and basket size - a small, high-watt unit runs slightly hotter and crowds sooner than a large drawer - which is exactly why the "check a few minutes early on the first attempt" advice matters more than any brand preset would. A calculator that showed different numbers per brand would be manufacturing precision that the brands themselves don't claim.