Is cooking at home that much cheaper?
09-03-2025
Cooking at home is, intuitively, cheaper. However, is it enough to actually matter? Or once you factor in energy costs, is it actually more expensive?
I decided to run some numbers on a stir fry and compare it to a ready meal, to see just how much cheaper cooking at home is.
Materials
I've turned to what is my personal recipe, which consists of a slightly modified teriyaki sauce, rice noodles, vegetable, and a generous portion of chicken:
- Mirin (25g)
- Soy sauce (125g)
- Ginger (100g)
- Sesame oil (16g)
- Shiitake mushrooms (150g)
- Bell Peppers (400g)
- Chicken (600g)
- Rice noodles (180g before absorbing water)
- Garlic (50g)
- Brocolli (300g)
In total, this makes about 2kg of food (wet/dry weight didn't change much, but vegetables/chicken shrunk by about 25% on average, whilst rice noodles easy soaked in 3x their original weight in water), which we will divide in 5 portions of 400g, as that is the size of our ready meal of choice.
Prices
Prices are as follows (prices were extracted from Waitrose in 09/03/2025, all ingredients shown are Waitrose's own in-house brand, except for the soy sauce, which is Kikkoman's, and the sesame oil, which is Lee Kum):
| Material | Weight per unit (kg) | Weight per recipe (kg) | Price per unit (GBP) | Price per recipe (GBP) |
|---|---|---|---|---|
| Mirin | 0.15 | 0.025 | 2.7 | 0.45 |
| Soy Sauce | 0.5 | 0.125 | 4.5 | 1.125 |
| Ginger | 0.1 | 0.1 | 0.62 | 0.62 |
| Shiitake mushrooms | 0.15 | 0.15 | 2.25 | 2.25 |
| Bell Peppers | 0.6 | 0.4 | 1.7 | 1.13 |
| Chicken | 1.2 | 0.6 | 6 | 3 |
| Rice Noodles | 0.18 | 0.18 | 1.25 | 1.25 |
| Garlic | 0.15 | 0.05 | 0.8 | 0.13 |
| Brocolli | 0.3 | 0.3 | 1.25 | 1.25 |
| Sesame Oil | 0.20 | 0.016 | 2.55 | 0.2 |
| Onion | 0.17 | 0.15 | 0.17 | 0.17 |
| Total | 3.70 | 2.09 | 23.79 | 12.04 |
You may note that there is a "per unit" column - this refers to the minimum unit you can buy of a given ingredient. However, for ingredients such as garlic, bell peppers and chicken, I've bought packs of items instead of individual units.
Since this gives us 4 portions, the price per portion is roughly 2.32 GBP, or, if we were to make 4 portions and throw away the excess items we bought, this would be 4.76 GBP. This is unrealistic, however, as many of these items have long shelf lives or can be frozen to be reused in other recipes.
This is, however, not considering energy costs. Assuming we're using an electric resistive hob, we'll be using 0.39 kWh of energy. As of March 2025, a kWh costs 27p in the UK, on average, giving us an energy cost of 10p.
Considering I boiled 750g of water from room temp (about 20 degrees celsius), and the average kettle has an efficiency of 80%, it took me 314kJ (0.09 kWh) (750*1*80*4.184/0.8) to bring that water up to a boil. In practice, what this means is that I wasted my time calculating this, since this is a paltry 2.5p.
With energy costs, our price per portion is now 2.37 GBP.
Comparision (ready meal)
We'll be comparing this to Tesco's own brand pre-made chow mein, costing 3.30 GBP for a similar portion size (or 2.66 GBP if you take them on their Clubcard deal). Note, however, that the ingredient disposition is much less favourable. A portion contains less than 80g of chicken (the "marinated chicken weight" includes corn starch and thickener agents), no brocolli/onion, and an unspecified amount of shiitake mushroom.
This means that cooking at home is, on average, 30p cheaper than a ready meal.
Making homemade meals cheaper
This homemade meal is still rather expensive, because I like shiitake mushrooms and chicken way too much. But if we remove the chicken and replace shiitake mushrooms with cup mushrooms (double the amount, priced at 1.10 GBP for 300g in Waitrose), the price per portion is now only 1.55 GBP.
There's also the slight detail that Waitrose is easily the most expensive widely available supermarket chain in the UK, so some ingredients (such as the chicken and oils) could be found cheaper elsewhere.
"What about the time you spent cooking/cleaning?"
I feel like this is an unfair thing to consider. Cooking is a hobby for many people, and factoring in "labour costs" is disingenuous. The notion that every living moment one has must be spent performing economically productive activities and/or preparing to do so (through studying, for instance) is a harmful notion, full stop. Instead of delving into labour theory of value, I opted to ommit time spent cooking.
If you only see cooking as a chore and you think it's unfair to exclude "labour costs", bill your local council for the time you spend showering and sleeping too. Time spent cooking is time you would not spend generating economic value anyway. If every waking moment in your life needs to be monetised, stop reading this and go work instead.
Economies of scale, corner casese, and bread
This does not always ring true for all recipes, though. If you don't mind living the rest of your life on certain items instant noodles and pasta, pre-made is going to be cheaper than making your own at home from scratch. Furthermore, in terms of calorific content, pure carbs are going to be much cheaper than eating vegetables and meat.
Bread is often times cheaper to purchase than to make at home. A loaf of bread, factoring energy costs and materials, takes about 90p to make, whilst bread can be purchased for 75p or cheaper. Homemade bread is much better, though.