# Human Readable Sizes

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When playing with large and small values, it is useful to convert them to a different unit in scientific notation. Let’s look at bytes.

```
size_categories = ["B", "KB", "MB", "GB", "TB"]
```

You can figure out how to best represent it by seeing how many of the base (in this case 1000) fits into the value. $$ category = \lfloor \frac{\log{(size_{bytes})}}{\log{(base)}} \rfloor $$ You’ll want to make sure that you don’t overflow in the number of categories you have

```
category_num = min(category_num, len(size_categories))
```

You can then get its category representation by $$ size = \frac{size_{bytes}}{(2^{category})} $$ We can wrap this all up info a nice python function

```
def humanReadableBytes(num_bytes: int) -> str:
base = 1000
# Zero Case
if num_bytes == 0:
return "0"
size_categories = ["B", "KB", "MB", "GB", "TB"]
category_num = int(math.log(num_bytes) / math.log(base))
# Make sure it doesn't overflow
category_num = min(category_num, len(size_categories) - 1)
return "{:.2f} ".format(num_bytes / (base ** category_num)) + \
size_categories[category_num]
```