diff --git a/src/docs/developers/build/differences.md b/src/docs/developers/build/differences.md
index 314ab213a..226e7e63a 100644
--- a/src/docs/developers/build/differences.md
+++ b/src/docs/developers/build/differences.md
@@ -132,6 +132,25 @@ See the full list of [custom JSON-RPC methods](./json-rpc.md) for more informati
 
 [Transaction costs on OP Mainnet](./transaction-fees.md) include an [L2 execution fee](./transaction-fees.md#the-l2-execution-fee) and an [L1 data fee](./transaction-fees.md#the-l1-data-fee). 
 
+### EIP 1559
+
+The L2 execution fee is calculated using [EIP-1559](https://notes.ethereum.org/@vbuterin/eip-1559-faq). The cost of a unit of gas is composed of two components:
+
+- **Base fee**: This fee is the same for all transactions in a block. It varies between blocks based on the difference between the actual size of the blocks (which depends on the demand for block space) and the target block size. When the block uses more gas than the target block size the base fee goes up to discourage demand. When the block uses less gas than the target block size the base fee goes down to encourage demand.
+- **Priority fee**: This fee is specified in the transaction itself and varies between transactions. Block proposers are expected to select the transactions that offer them the highest priority fees first.
+
+The EIP 1559 parameters are different:
+
+  | Parameter | OP Mainnet value | Ethereum value (for reference) |
+  | - | -: | -: |
+  | Block gas limit | 30,000,000 gas | 30,000,000 gas
+  | Block gas target | 5,000,000 gas | 15,000,000 gas
+  | EIP-1559 elasticity multiplier | 6 | 2
+  | EIP-1559 denominator | 50 | 8
+  | Maximum base fee increase (per block) | 10% | 12.5%
+  | Maximum base fee decrease (per block) | 2% | 12.5%
+  | Block time in seconds | 2 | 12
+
 
 ## Contract addresses