Quick Answer
Bake salmon at 400°F for 12–15 minutes for a 1-inch thick fillet, or until the internal temperature reaches 125–130°F (medium) to 145°F (fully cooked). Cooking time varies based on thickness, whether it’s foil-wrapped, and if it’s fresh or frozen.
Baking salmon at 400°F is the sweet spot for most home cooks. It’s hot enough to cook the fish quickly and create a lightly caramelized exterior, but gentle enough that it stays moist and flaky inside — not dry and chalky.
Whether you’re baking a whole side of salmon, individual fillets, or cooking straight from frozen, this guide covers every scenario so you get perfectly cooked salmon every single time.
1. Baking Times by Thickness and Type- How Long to Bake Salmon at 400 Degrees
The number-one rule of baking salmon: thickness matters more than weight. A 6-oz fillet and a 4-oz fillet can have the same thickness. Always use a ruler or eyeball the thickest part, not the package weight.
| Type / Thickness | Oven Temp | Bake Time | Notes |
|---|---|---|---|
| Thin fillet (½ inch) | 400°F | 8–10 min | Watch carefully — cooks fast |
| Standard fillet (1 inch) | 400°F | 12–15 min | Most common home-cook scenario |
| Thick fillet (1½ inch) | 400°F | 15–18 min | Centre-cut portions, king salmon |
| Whole side / large piece | 400°F | 18–22 min | Check internal temp at 18 min |
| Frozen (1 inch, unwrapped) | 400°F | 20–25 min | Add 10–13 min to fresh time |
| In foil packet (1 inch) | 400°F | 15–18 min | Steams; stays extra moist |
2. How to Know When Salmon Is Done
Time is a guide — temperature is the truth. Never rely on time alone, as every oven runs slightly different, and fish thickness varies wildly.
Use an instant-read thermometer
Insert it into the thickest part of the fillet without touching the pan. Here’s what the numbers mean:
Internal Temperature Guide
- 110–115°F — Rare / sushi-like. Translucent, very soft centre.
- 120–125°F — Medium-rare. Silky, moist, slightly translucent. Restaurant-style.
- 125–130°F — Medium. Fully opaque, tender and flaky. Our recommended sweet spot.
- 145°F — USDA fully cooked. Completely opaque, firm, food-safe for all diners.
- Above 150°F — Overcooked. Dry, chalky, white albumin leaching out.
The fork test (no thermometer)
Slide a fork or thin knife into the thickest part and twist gently. If the flesh flakes apart in large, clean layers and appears opaque throughout, it’s done. If it resists or looks translucent in the centre, give it 2–3 more minutes.
The white albumin cue
That white, creamy substance that oozes out of salmon as it cooks is called albumin — it’s a protein that solidifies with heat. A little is normal and fine. A lot pooling on the surface means the fish is cooking too fast or is past its prime. Lower your oven temperature slightly for next time.
3. Foil vs. Uncovered — Which Is Better? – How Long to Bake Salmon at 400 Degrees
Both methods work beautifully at 400°F, but they produce different results.
Foil vs. Uncovered
- Uncovered: Slight crust forms on top. Roasty, caramelized flavour. Better for skin-on fillets. Needs 12–15 min for 1-inch.
- Foil-wrapped: Steams in its own juices. Ultra moist, delicate texture. Great for adding aromatics (lemon, herbs, garlic). Needs 15–18 min for 1-inch.
- Parchment (en papillote): Like foil, but the paper puffs up dramatically — elegant for dinner parties. Same timing as foil.
Our recommendation: go uncovered for weeknight simplicity and crispy skin; use foil packets when cooking for a crowd or when adding a marinade you don’t want to burn.
4. Tips for the Best Baked Salmon at 400°F – How Long to Bake Salmon at 400 Degrees
Pro Tips
- Bring it to room temperature. Pull the salmon from the fridge 15–20 minutes before baking. Cold fish from the fridge cooks unevenly.
- Pat it completely dry. Moisture on the surface steams instead of roasts. Use paper towels and press firmly.
- Oil the pan, not just the fish. A lightly oiled pan or a rack set inside a sheet pan prevents sticking and promotes even heat.
- Season generously. Salt at least 15 minutes before cooking (or overnight) for the best flavour penetration.
- Skin-side down, always. The skin acts as a heat buffer and keeps the flesh moist. Don’t flip it.
- Rest for 3 minutes. Like steak, salmon benefits from a brief rest after the oven. Carryover cooking adds 3–5°F.
- Line your pan with foil for easy cleanup. Salmon fat can bake onto pans and is notoriously hard to remove.
5. Frequently Asked Questions – How Long to Bake Salmon at 400 Degrees
Can I bake salmon at 400°F from frozen?
Yes. Place frozen fillets on a lined baking sheet, brush with oil, season, and bake uncovered for 20–25 minutes for a 1-inch fillet. There’s no need to thaw. Just be aware the texture will be slightly firmer than fresh-baked.
Is 400°F or 425°F better for salmon?
400°F is more forgiving — you have a wider margin before the fish dries out. 425°F is faster (10–12 min) but demands precise timing. For beginners, stick to 400°F. Experienced cooks who want a quicker cook can bump it to 425°F.
What temperature is salmon fully cooked according to the USDA?
The USDA recommends an internal temperature of 145°F for fish. However, many chefs and food-safe guidelines allow for 125–130°F (medium) for healthy adults, since salmon continues to cook slightly after being removed from the oven.
How do I keep salmon moist in the oven?
Three key strategies: (1) don’t overcook it — pull it at 125–130°F, (2) wrap it in foil to trap steam, and (3) baste it with butter or oil halfway through baking. A marinade with an acid (lemon juice, soy sauce) also helps retain moisture.
Should I cover salmon with foil when baking at 400°F?
It depends on your goal. Foil = moist and tender. No foil = slightly crisp exterior. Both are correct — it’s a matter of preference. If you’re adding a glaze or sauce, foil for the first half and uncovered for the last few minutes gives you the best of both worlds.
Can I bake salmon in a glass dish at 400°F?
Yes. Glass baking dishes (like Pyrex) work well at 400°F. They retain heat slightly longer than metal pans, so your salmon may continue cooking a bit after removal. Pull it 2–3 minutes earlier than you would with a metal sheet pan.
The Bottom Line
For most salmon fillets, bake at 400°F for 12–15 minutes, skin-side down on a lined baking sheet. Use an instant-read thermometer and aim for 125–130°F for moist, restaurant-quality results. Adjust by 2–3 minutes per half-inch of thickness, and always let it rest before serving.
Master this single formula and you’ll never have dry, overcooked salmon again. Once it’s second nature, experiment with glazes, foil packets, and marinades — the possibilities are endless.
