Klaytn uses a similar transaction fee model as Ethereum does — Gas. All transactions are required to pay fees in **KLAY** in order to get accepted and included in blocks.

Quick Recap: KLAY is the main internal transferable token of Klaytn

## Gas Fee Calculation

Total gas fee an arbitrary transaction must pay can be calculated as follows:

```
Total Gas Fee = Gas Price x Gas Used
```

In Klaytn, gas price is constant which is set to **25 ston**. Wait, **ston**? Not, **KLAY**? What is ston anyway? Here’s a conversion table you might find helpful.

| Unit | peb value | peb |

|—|—|—|—|

| peb | 1 peb | 1 |

| kpeb | 10^3 peb | 1,000 |

| Mpeb | 10^6 peb | 1,000,000 |

| Gpeb (a.k.a. **ston**) | 10^9 peb | 1,000,000,000 |

| KLAY | 10^18 peb | 1,000,000,000,000,000,000 |

*The above table is a part of the full version available here.*

Accodring to the table, 25 ston is 25,000,000,000 peb and equal to 0.000000025 KLAY. Okay, now we can calculate how much gas fee one transaction must pay: you just multiply 25 to the amount of gas the transaction used and divide it by 10^9.

FYI, you can look up your transaction receipt for gas used (with key `gasUsed`

).

## Gas Fee Example

Nothing explains better than one good example. So, here’s an example. A simple value transfer transaction takes 21,000 gas. The following calculates the amount of gas fee in KLAY for a value transfer.

```
1) Gas Price x Gas Used = Total Gas Fee
2) 25 ston x 21,000 = 525,000 ston
3) 525,000 ston / (10^9 ston/KLAY) = 525 x 10^-6 KLAY = 0.000525
```

So the gas fee is 0.000525 KLAY. Simple, right?