If you want to throw a party where you spare no effort but no expense, then the idea of simply ordering pizza from the local supplier quickly comes to mind. At a party, however, many people often come together, and the tasty pizzas are delivered in a classic **round shape** and there is also the option of ordering different sizes. So this is about the round pizzas and not the square party pizza that you make on the baking tray.

This quickly raises the question of how many pizzas you need to calculate in total to feed everyone? But perhaps there should still be a little something left over. After all, when everything has been eaten, the friendly guests will claim that they are already full and the host will secretly think that he is telling a white lie and that he is behind the obituary of a stingy caterer.

## Main approach/standard pizza: How many pizzas does one person eat?

The main problem with ordering pizza from pizzerias and pizza delivery companies is that round pizzas usually come in different sizes. There is the jumbo or family pizza, large, medium, small, etc.

This means that when calculating how many pizzas you need to order for the party, you need to determine how many pizzas one person can eat. You can then take the surface area and scale it upwards.

I took myself as an example, and I know that I am full from a frozen pizza à la Dr. Oetker or Wagner. Actually too full, but at parties and social gatherings we always go a bit overboard.

These pizzas have a diameter of 25 cm.

Our **standard pizza** for one adult for further calculation is therefore **25 cm** in diameter.

## Weigh the number of people

In the next step, you can literally **weight your guests** 😊 to determine a calculated number of guests. Because not everyone can manage a standard 25 cm pizza. My approach to weighting is:

- Male adult: 1
- Female adult: 0.75
- Children < 10 years: 0.5
- Pensioner > 80 years: 0.6

Slightly more corpulent people or overtrained marathon runners, who are known to be good food converters, can also be calculated with up to 1.5. But be careful not to embarrass a guest.

So if you had a party with **20 people, 4 of whom are children, 2 pensioners, 7 male and 7 female,** this would result in a **calculated number of people** of 15.45, rounded up to **16 people**. Always round up nicely, there should be something left over.

So you would need at least **16 standard pizzas with a diameter of 25 cm**.

## Convert to another pizza size

However, you may not want to order 16 small pizzas, but rather the medium size (e.g. 28 cm diameter) or the even larger ones (32 cm diameter).

### Calculate total surface area

Well, you simply have to calculate the total surface area and then put it in proportion. The area of our standard pizza is calculated using the circular formula circle number pi times diameter squared divided by 4:

${A}_{Pizza}=\mathrm{\pi}\times \frac{{\mathrm{d}}^{2}}{4}$

This corresponds to 490.87 cm² for our standard pizza. Multiplied by the calculated number of people, this results in

${A}_{Gesamt}=Persons{Calc}_{}\times \mathrm{\pi}\times \frac{{\mathrm{d}}^{2}}{4}$

**7853.98 cm² total area**

### Calculating the number of medium and large pizzas

Now use the circular formula to calculate the individual area of the medium or large pizza

- Medium pizza D = 28 cm: 615.75 cm²
- large pizza D = 32 cm: 804.25 cm²

and sets this in relation to the total area required:

- medium pizza D = 28 cm: 7853.98 cm²/615.75 cm² = 12.76 (rounding up
**13 pizzas**) - large pizza D = 32 cm: 7853.98 cm²/804.25 cm² = 9.77 (round up
**10 pizzas**)

Again, always round up nicely, we want to have some left over for the hangover breakfast.

## Example: How many pizzas for 10 people?

For those who need a quick, **short answer**. Let’s assume it’s a small family gathering of **4 women, 4 men and 2 children**. With the approach described above, you then need either:

- 8 small pizzas (25 cm), or
- 7 medium pizzas (28 cm), or
- 5 large pizzas (32 cm)

## Example: How many pizzas for 15 people

And here again for a variant with 15 guests: Let’s assume that the guests to be catered for consist of **6 men, 6 women and 3 children**. With the approach described above, you then need either:

- 12 small pizzas (25 cm), or
- 10 medium pizzas (28 cm), or
- 8 large pizzas (32 cm)

## Pizza calculator for download

The whole derivation and calculation process is probably a bit tedious for most people. The local pizza delivery service may offer different pizza sizes. You may also want to vary a little and add a 20% surcharge.

That’s why I quickly made my calculation in Excel. You can download the Excel file to calculate how many pizzas you need per person or party here.