Reverse Sear Timing Calculator: low-oven time, pull temperature and sear
Plan a reverse-seared steak or roast: the low-oven or smoker time to reach your pull temperature from steak thickness or roast diameter, oven temperature, starting temperature and fan, then the sear, final temperature, a cooking timeline and a time-by-thickness chart.
How it works
Pull = final − gap (default 15 °F) · θ = (pull − oven) ÷ (start − oven) · Bi = h × L ÷ k with L = half the thickness (steak) or the radius (roast) · ζ tan ζ = Bi (slab) or ζ J₁(ζ)/J₀(ζ) = Bi (cylinder) · time = L² ÷ α × ln(C ÷ θ) ÷ ζ² · with k = 0.47 W/m·K, α = 1.3 × 10⁻⁷ m²/s, h ≈ 24 W/m²·K (×1.5 with a fan)
Reverse searing flips the usual order: the meat cooks gently in a low oven or smoker until it is close to done, then gets a short blast of high heat for the crust. Because the inside rises slowly and evenly, you get edge-to-edge pink instead of a grey band, and the dried surface browns fast. The calculator predicts the low-oven time with the standard heat-conduction solution for a slab (steak) or a cylinder (roast): the center warms toward the oven temperature exponentially, and the time grows a bit faster than the thickness, so a 3-inch steak takes far more than twice as long as a 1.5-inch one. The oven-air heat-transfer coefficient is set so a 1.5-inch steak from the fridge reaches 115 °F at 250 °F in about 36 minutes and 120 °F at 200 °F in about 52 minutes, in line with published reverse-sear time charts; a fan or a breezy smoker speeds it up by about a third. You pull the meat about 15 °F below the target because the sear and carryover heat push it the rest of the way, and you can change that gap. Treat the time as a schedule and the thermometer as the answer: thickness varies across a steak and many ovens run 25 °F off.
Worked example
A 1.5-inch steak for medium-rare (130 °F final) at 250 °F from 38 °F: the pull is 130 − 15 = 115 °F. The temperature ratio is (115 − 250) ÷ (38 − 250) = 0.637. With L = 0.75 in (0.019 m), Bi = 24 × 0.0191 ÷ 0.47 = 0.97, giving ζ = 0.852 and C = 1.117, so the Fourier number is ln(1.117 ÷ 0.637) ÷ 0.852² = 0.775. L² ÷ α is 46.5 minutes, so the time is 0.775 × 46.5 ≈ 36 minutes (likely 29 to 45 minutes; start checking at 25). Then sear about 2 minutes in a smoking-hot pan to finish at 130 °F; with a 15-minute preheat the whole cook takes about 53 minutes.
Sources: FoodSafety.gov: safe minimum internal temperatures · Inkbird: how to reverse sear steak (250 °F oven times by doneness) · Wholesome Yum: reverse sear steak (200 °F oven time chart)
Frequently asked questions
How long does a reverse sear take?
In a 250 °F oven, a 1-inch steak takes roughly 20 minutes, a 1.5-inch steak about 35 minutes and a 2-inch steak just under an hour to reach a medium-rare pull temperature, plus a couple of minutes of searing. A thick roast can take 2 to 4 hours.
Why pull the steak below the final temperature?
The high-heat sear and carryover heat keep raising the internal temperature after it leaves the low oven. Pulling about 15 °F early means it lands on target after searing instead of overshooting.
What oven temperature is best for a reverse sear?
Anything from about 200 to 275 °F works. Lower temperatures give a more even interior and a wider window to pull, but take longer; 250 °F is a common compromise.
What steaks suit a reverse sear?
Thick cuts of at least 1¼ inches, ideally 1½ to 2 inches, such as ribeye, strip, porterhouse or thick filet, plus roasts like prime rib and tenderloin. Thin steaks cook through before a crust forms, so sear them directly.
Do I need to rest a reverse-seared steak?
Hardly at all. The gentle cook leaves little temperature difference between the edge and the center, so juices stay put; serve within a few minutes of searing. Roasts benefit from a 10 to 20 minute rest before or after the sear.
Is medium-rare safe?
USDA guidance for whole cuts of beef, pork and lamb is 145 °F with a 3-minute rest. Many cooks serve steaks at 125 to 135 °F; bacteria are mostly on the surface, which the sear treats, but ground meat and at-risk eaters should follow the USDA figure.
Related calculators
Cooking times are estimates; always confirm doneness with a food thermometer.