Master the Roast: How Long to Cook Pork Per Kg

There is nothing quite like the comforting aroma of a pork roast wafting through the kitchen. Whether you are aiming for a classic Sunday roast complete with ultra-crispy crackling, or a melt-in-your-mouth slow-cooked joint, getting the timing right is everything. Cook it too little, and you miss out on texture; cook it too much, and you lose that precious juiciness.

To help you achieve culinary perfection, here is a complete, foolproof guide to calculating exactly how long to cook pork per kilogram.

The Golden Rule of Pork Cooking Times

As a general rule of thumb for standard cuts like a pork loin, leg, or shoulder, you should calculate your roasting time based on weight, keeping a buffer for extra crispiness:

• Standard Roasting Time: Roughly 40 to 45 minutes per kg, plus an extra 20 to 30 minutes total cooking time.
• The High-Heat Blast Method: Many chefs recommend starting the pork at a high temperature (around 220°C / 200°C Fan) for the first 30 minutes to blister the skin and create crackling, then dropping the oven down to 180°C / 160°C Fan for the remainder of the per-kg calculation.

Quick Reference: Cooking Times by Weight

Assuming an oven set at 180°C (after an initial high-heat sear if doing crackling), here is roughly how long common joint sizes will take:

| Weight of Pork Joint | Total Estimated Cooking Time |
| :— | :— |
| 1 kg | 1 hour to 1 hour 10 minutes |
| 1.5 kg | 1 hour 30 minutes to 1 hour 45 minutes |
| 2 kg | 2 hours to 2 hours 15 minutes |
| 2.5 kg | 2 hours 30 minutes to 2 hours 45 minutes |

Note: These times are guidelines. Cuts with bone-in tend to take slightly longer to conduct heat to the center compared to boneless roasts.

Cut-by-Cut Breakdown

Not all pork cuts are created equal. Depending on what you pulled out of the butcher’s wrapping, your strategy might shift:

1. Pork Loin & Leg (Classic Roasts)

• Time: ~40 minutes per kg.
• Best for: Traditional carving slices. If it has a skin layer (rind), score it finely, rub it generously with sea salt, and use the high-to-low temperature method to guarantee epic crackling.

2. Pork Shoulder (The Slow-Roast Champion)

• Time: ~45 to 50 minutes per kg, or low-and-slow at 150°C for 4 to 5 hours.
• Best for: Pulled pork. Pork shoulder has a higher fat content, which means it thrives on longer, slower cooking. This breaks down the connective tissue until the meat easily pulls apart with two forks.

3. Pork Fillet (Tenderloin)

• Time: Roughly 20 to 25 minutes total per 500g (about 30 to 40 minutes for a whole fillet).
• Best for: Quick weeknight dinners. Because it’s a very lean cut, it dries out fast. Pan-sear it first, then pop it into an oven preheated to 180°C.

The Ultimate Test: Temperature Trumps Time

While math and kitchen scales are a great starting point, the absolute foolproof way to know your pork is ready is by using a meat thermometer.