Fish Cook Time Calculator
Fish minutes from thickness and method, with 145 F finish and flip splits.
What it does
Fish finishes by thickness, not weight: heat must reach the center of the thickest point, and one rule covers most dry methods at 10 minutes per inch with a flip halfway. Foil insulates, frozen doubles, and 145 F closes every path.
The tool above takes thickness with the method. It returns total time with per side splits and the finish check.
The default 1.5 in fillet bakes 15 min as 7.5 per side. The metric mirror of 38 mm reads the same, while foil stretches it to 20.
Rules follow FDA seafood guidance with Foodsafety.gov temperatures and Clemson extension method notes behind them. All three agree on 145 F and the 10 minute rate used here.
How to use
- Pick inches or millimeters.
- Measure the thickest point.
- Pick the cooking method.
- Read total time first.
- Split per side for the flip.
- Check 145 F and flaking.
Formula
- thickness
- Thickest point in inches.
- 10 min
- Uncovered rate per inch.
- +5 min
- Insulation adder for foil or sauce.
- 20 min
- Frozen rate per inch.
Millimeters convert to inches first (divide by 25.4), then the same rule runs. Measure stuffed or rolled fish after shaping. Under 0.5 in needs no flip; microwaves and deep fryers need their own clocks.
Worked example
Example: 1.5 inch fillet
Imperial defaults: 1.5 in fillet, baked uncovered.
- Thickness: 1.5 in at the thickest point.
- Rate: 10 min per inch uncovered.
- Total: 1.5 x 10 = 15 min.
- Sides: 15 / 2 = 7.5 min each, turn once.
- Finish: 145 F with opaque flaking flesh.
- Metric check: 38 mm cooks the same 15 min.
- Tool shows 15 min total, 7.5 min per side, 145 F + flake check.
Reference table
| Method | Rate | Note |
|---|---|---|
| Bake / broil / grill | 10 min/in | Turn halfway at 0.5 in+ |
| In foil or sauce | 10 min/in + 5 | Insulation adder |
| From frozen | 20 min/in | Double, verify temp |
| Microwave | 3 min/lb | Rotate halfway, separate rule |
Limits
- Fillets and steaks; microwave needs its own rule.
- Deep frying runs hotter and faster.
- Shellfish follow open-shell rules.
- At-risk groups avoid raw seafood.
Common mistakes
- Measuring thin edges instead of thickest.
- Skipping the flip on thick fish.
- Forgetting the foil 5 min.
- Using bake times from frozen.
- Serving closed shells.
Try it yourself
Quick checks. Answers sit tucked under each question.
1.5 in fillet in foil?
15 + 5 = 20 min total, 10 min per side.
1 in steak from frozen?
1 x 20 = 20 min total from frozen.
0.25 in fillet, baked?
0.25 x 10 = 2.5 min total, no flip needed.
Questions
When is fish done?
145 F, or opaque flesh that flakes easily. Shrimp go firm and pearly; shells must open.
Does the 10 minute rule hold?
Yes: 10 min per inch uncovered, turn halfway for pieces 0.5 in or thicker.
What changes in foil or sauce?
Add 5 min total for insulation. A 1.5 in fillet runs 20 min in foil.
What if the fish is frozen?
Double to 20 min per inch and verify 145 F. Do not apply microwave times here.
How long in the microwave?
About 3 min per lb boneless on high, thicker parts outward, rotate halfway. Rolled fillets even out.
What about unopened shells?
Throw out clams, mussels, and oysters whose shells stay shut through cooking.