You’ll usually bake salmon at 400°F for about 10–20 minutes, depending mainly on thickness and whether it’s fresh or frozen.

Quick Scoop (Short Answer)

  • Fresh salmon fillets at 400°F: about 10–15 minutes for a piece around 1 inch thick.
  • Thicker fillets (1½ inches or more): about 18–20 minutes.
  • Frozen salmon at 400°F: often 20–30 minutes depending on thickness.
  • Target internal temperature: 145°F at the thickest part (US food safety guideline).

Rule of Thumb at 400°F

  • Many cooks use roughly 10 minutes per inch of thickness at 400°F as a starting guide.
  • For typical portions:
    • Thin fillet (about ½ inch): 10–12 minutes.
    • Medium fillet (about 1 inch): 12–15 minutes.
    • Thick fillet (1½+ inches): 18–20 minutes.

The fish is done when it flakes easily with a fork and looks opaque, not glassy, in the center.

If Salmon Is In Foil or Frozen

  • Salmon baked in foil at 400°F:
    • Thin: ~12–15 minutes.
    • Medium: ~15–18 minutes.
    • Thick: ~18–20 minutes.
  • Frozen salmon at 400°F:
    • Thin portions: ~20–25 minutes.
    • Medium (about 1 inch): ~25–30 minutes.
    • Thick: ~30–35 minutes.

Foil and frozen starts trap more moisture and require a bit more time, so start checking a few minutes before the upper range.

Simple Step‑By‑Step Example

  1. Preheat oven to 400°F.
  2. Pat salmon dry, brush with oil, and season with salt, pepper, and any herbs.
  3. Place skin‑side down on a lined baking tray (or wrapped loosely in foil).
  4. Bake:
    • 1‑inch fresh fillet: check at 10–12 minutes, then every 2 minutes.
  1. Check internal temperature with a thermometer; remove around 135–140°F, let rest a few minutes to reach about 145°F.

Time and Thickness Table (400°F)

[3][5] [1][3][5] [3][5] [5] [5]
Salmon type Thickness Approx. time at 400°F Notes
Fresh fillet ½ inch 10–12 minutes Check early; cooks fast.
Fresh fillet 1 inch 12–15 minutes Very common size; most recipes fall here.
Fresh fillet 1½+ inches 18–20 minutes Use a thermometer to avoid under/overcooking.
Foil‑wrapped ½–1½+ inches 12–20 minutes Range widens because foil traps steam.
Frozen portions ½–1½+ inches 20–35 minutes Add roughly 10–15 minutes vs. fresh.

TL;DR: For most home dinners, a standard 1‑inch fresh salmon fillet baked at 400°F will be ready in about 12–15 minutes; start checking early and trust your thermometer and the flakes. 🕒

Information gathered from public forums or data available on the internet and portrayed here.