The Science Behind Cooking the Perfect Steak
The exact formula for cooking the perfect steak has been revealed by a scientist-chef just in time for Father’s Day, and it’s all down to how heat moves through meat.
Professor Rob Appleby, a physicist from the University of Manchester and trained chef, says the answer lies in a formula first worked out by Albert Einstein:
L² = 4Dt
L represents the thickness of the steak, T is the time for the steak to cook, and D is something called the diffusion coefficient (the speed at which heat moves through the steak).
This scientific equation, originally used to describe the motion of particles, can be applied to predict how long it takes for heat to penetrate and perfectly cook a steak.
“Steak science is surprisingly precise,” says Rob. “It’s not the weight of the steak that matters, but its thickness. Heat takes longer to travel through thicker meat, and Einstein’s formula helps us understand exactly how long it takes.”
According to Rob, the time it takes to cook a steak increases with the square of its thickness. That means doubling the thickness of a steak doesn’t just double the cooking time – it can quadruple it.
This insight busts one of the biggest BBQ myths: that a steak twice as big takes twice as long to cook. It takes longer! In fact, it’s all about how deep the heat needs to travel, and that’s something you can calculate using physics.
By using the formula and a simple temperature probe, home cooks can avoid overcooking, undercooking, or the dreaded burnt-outside, raw-inside BBQ disasters.
“A 2cm-thick steak might take just 4 minutes total, while a 4cm steak could take over 12 minutes,” says Rob.
A simplified timing chart based on Prof Appleby’s formula has been created for home chefs, helping anyone master steak cooking based on thickness:
Cooking Time Chart (for medium-rare at core)
| Steak Thickness (cm) | Estimated Time Per Side (minutes) | Total Cooking Time (minutes) |
| 1.5 cm | 1.5-2 | ~3-4 |
| 2.0 cm | 2-2.5 | ~4-5 |
| 2.5 cm | 3-4 | ~6-8 |
| 3.0 cm | 4-5 | ~8-10 |
| 4.0 cm | 6-7 | ~12-14 |
Add ~1-2 minutes per side if you’re aiming for medium or medium-well.
The timing is perfect for Father’s Day weekend, when millions of dads will be firing up their grills. Josh Novell from Polhill BBQs, who helped create the chart, says:
“People are always nervous about steak, especially on a BBQ, but this takes the guesswork out. You don’t need to be a physicist; just have the right tools and the right method.”
“When you’re cooking over flames or coals, heat zones vary and it’s easy to burn the outside before the centre’s ready. But by understanding how heat travels through the steak, you avoid solely relying on instinct.”
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Professor Rob Appleby is a physicist at the University of Manchester whose research focuses on particle motion, and he is also a trained chef from Leith’s School of Food and Wine. As a world-leading science communicator and recipient of the European Physics Society’s Prize for Scientific Outreach, Rob is uniquely skilled at translating complex scientific concepts into practical advice.
Josh Novell is a BBQ expert at Polhill BBQs and leads the popular Polhill BBQ School, which offers masterclasses for enthusiasts.