Gravy Calculator

The classic roux-based gravy ratio is 30g fat : 30g flour : 500ml stock for 4 servings. The fat can be dripping from the roasting tin, butter, or a combination. Equal weight of fat and flour makes the roux; the stock is then added gradually to achieve a smooth gravy. For thicker gravy, use a slightly larger roux (more fat AND flour, keeping them equal) with a touch less stock; for thinner gravy, use a smaller roux with more stock.

The key to lump-free gravy is adding the stock gradually. Cook the fat and flour together for 1-2 minutes to make a roux, then remove from the heat. Add the stock a splash at a time, whisking constantly after each addition until smooth before adding more. Once half the stock is in, you can add the rest more quickly. Always whisk rather than stir. If lumps form, push through a sieve.

Use stock that matches the meat you are roasting: chicken stock for chicken, beef stock for beef, etc. Homemade stock gives the best flavour, but a good quality stock cube or concentrated stock pot works well. The roasting tin juices (deglazed with a splash of wine or stock) should always be included — this is where most of the flavour comes from.

Yes, gravy reheats well. Make it up to 2 days ahead, cool quickly, and refrigerate in an airtight container. Reheat gently in a saucepan, adding a splash of stock if it has thickened too much. Gravy also freezes for up to 3 months. Making gravy ahead takes pressure off on the day of a roast dinner.

As a guide, allow 100-150ml of gravy per person for a roast dinner. This calculator bases quantities on approximately 125ml per person. For gravy lovers or if you want leftovers, increase by 50%. It is always better to have too much gravy than too little.