diff --git a/index.d.ts b/index.d.ts
index 4a3a5f3..58eabe9 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -7,9 +7,13 @@ export interface UTXO {
         script: Buffer,
         value: number
     }
+    redeemScript?: Buffer,
+    witnessScript?: Buffer,
+    isTaproot?: boolean
 }
 export interface Target {
-    address: string,
+    address?: string,
+    script?: Buffer,
     value?: number
 }
 export interface SelectedUTXO {
diff --git a/test/fixtures/accumulative.json b/test/fixtures/accumulative.json
index 23505d5..73e761f 100644
--- a/test/fixtures/accumulative.json
+++ b/test/fixtures/accumulative.json
@@ -163,7 +163,7 @@
     "feeRate": 5,
     "inputs": [
       {
-        "script": {
+        "redeemScript": {
           "length": 1000
         },
         "value": 3000
@@ -220,7 +220,7 @@
     "feeRate": 5,
     "inputs": [
       {
-        "script": {
+        "redeemScript": {
           "length": 500
         },
         "value": 3000
@@ -239,7 +239,7 @@
       "inputs": [
         {
           "i": 0,
-          "script": {
+          "redeemScript": {
             "length": 500
           },
           "value": 3000
@@ -272,7 +272,7 @@
         "value": 3000
       },
       {
-        "script": {
+        "redeemScript": {
           "length": 400
         },
         "value": 3000
@@ -672,7 +672,7 @@
     "inputs": [
       20000,
       {
-        "script": {
+        "redeemScript": {
           "length": 300
         },
         "value": 10000
@@ -691,7 +691,7 @@
         },
         {
           "i": 1,
-          "script": {
+          "redeemScript": {
             "length": 300
           },
           "value": 10000
diff --git a/test/fixtures/index.json b/test/fixtures/index.json
index 9ebcdbf..3cff1dc 100644
--- a/test/fixtures/index.json
+++ b/test/fixtures/index.json
@@ -136,7 +136,7 @@
     "feeRate": 5,
     "inputs": [
       {
-        "script": {
+        "redeemScript": {
           "length": 1000
         },
         "value": 3000
@@ -175,7 +175,7 @@
     "feeRate": 5,
     "inputs": [
       {
-        "script": {
+        "redeemScript": {
           "length": 500
         },
         "value": 3000
@@ -220,7 +220,7 @@
         "value": 3000
       },
       {
-        "script": {
+        "redeemScript": {
           "length": 400
         },
         "value": 3000
@@ -620,7 +620,7 @@
     "inputs": [
       20000,
       {
-        "script": {
+        "redeemScript": {
           "length": 300
         },
         "value": 10000
@@ -804,6 +804,315 @@
       10000
     ],
     "expected": {}
+  },
+  {
+    "description": "segwit mainnet input and output",
+    "feeRate": 10,
+    "inputs": [{
+      "value": 103430,
+      "witnessUtxo": {
+        "script": "script public key",
+        "value": 103430
+      }
+    }],
+    "outputs": [
+      {
+        "value": 100000,
+        "address": "bc1q34aq5drpuwy3wgl9lhup9892qp6svr8ldzyy7c"
+      }
+    ],
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 103430,
+          "witnessUtxo": {
+            "script": "script public key",
+            "value": 103430
+          }    
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000,
+          "address": "bc1q34aq5drpuwy3wgl9lhup9892qp6svr8ldzyy7c"
+        },
+        {
+          "value": 2000
+        }
+      ],
+      "fee": 1430
+    }
+  },
+  {
+    "description": "segwit testnet input and output",
+    "feeRate": 10,
+    "inputs": [{
+      "value": 103430,
+      "witnessUtxo": {
+        "script": "script public key",
+        "value": 103430
+      }
+    }],
+    "outputs": [
+      {
+        "value": 100000,
+        "address": "tb1q34aq5drpuwy3wgl9lhup9892qp6svr8ldzyy7c"
+      }
+    ],
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 103430,
+          "witnessUtxo": {
+            "script": "script public key",
+            "value": 103430
+          }    
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000,
+          "address": "tb1q34aq5drpuwy3wgl9lhup9892qp6svr8ldzyy7c"
+        },
+        {
+          "value": 2000
+        }
+      ],
+      "fee": 1430
+    }
+  },
+  {
+    "description": "p2sh mainnet output",
+    "feeRate": 10,
+    "inputs": [
+      105000
+    ],
+    "outputs": [
+      {
+        "value": 100000,
+        "address": "3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy"
+      }
+    ],
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 105000
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000,
+          "address": "3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy"
+        },
+        { 
+          "value": 2760 
+        }
+      ],
+      "fee": 2240
+    }
+  },
+  {
+    "description": "p2sh testnet output",
+    "feeRate": 10,
+    "inputs": [
+      105000
+    ],
+    "outputs": [
+      {
+        "value": 100000,
+        "address": "2J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy"
+      }
+    ],
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 105000
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000,
+          "address": "2J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy"
+        },
+        { 
+          "value": 2760 
+        }
+      ],
+      "fee": 2240
+    }
+  },
+  {
+    "description": "p2wsh or taproot mainnet output",
+    "feeRate": 10,
+    "inputs": [
+      104010
+    ],
+    "outputs": [
+      {
+        "value": 100000,
+        "address": "bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak"
+      }
+    ],    
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 104010
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000,
+          "address": "bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak"
+        },
+        {
+          "value": 1660
+        }
+      ],
+      "fee": 2350
+    }
+  },
+  {
+    "description": "p2wsh or taproot testnet output",
+    "feeRate": 10,
+    "inputs": [
+      104010
+    ],
+    "outputs": [
+      {
+        "value": 100000,
+        "address": "tb1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak"
+      }
+    ],    
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 104010
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000,
+          "address": "tb1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak"
+        },
+        {
+          "value": 1660
+        }
+      ],
+      "fee": 2350
+    }
+  },
+  {
+    "description": "taproot input",
+    "feeRate": 10,
+    "inputs": [{
+      "value": 103360,
+      "isTaproot": true
+  }],
+    "outputs": [
+      100000
+    ],
+    "expected": {
+      "inputs": [
+        {
+          "i": 0,
+          "value": 103360,
+          "isTaproot": true
+        }
+      ],
+      "outputs": [
+        {
+          "value": 100000
+        },
+        {
+          "value": 2000
+        }
+      ],
+      "fee": 1360
+    }
+  },
+  {
+    "description": "1 output, passes, skipped detrimental input",
+    "feeRate": 5,
+    "inputs": [
+      {
+        "redeemScript": {
+          "length": 1000
+        },
+        "value": 3000
+      },
+      {
+        "value": 3000
+      },
+      {
+        "value": 3000
+      }
+    ],
+    "outputs": [
+      4000
+    ],
+    "expected": {
+      "fee": 2000,
+      "inputs": [
+        {
+          "i": 1,
+          "value": 3000
+        },
+        {
+          "i": 2,
+          "value": 3000
+        }
+      ],
+      "outputs": [
+        {
+          "value": 4000
+        }
+      ]
+    }
+  },
+  {
+    "description": "1 output, passes, skipped detrimental input",
+    "feeRate": 5,
+    "inputs": [
+      {
+        "witnessScript": {
+          "length": 4000
+        },
+        "value": 3000
+      },
+      {
+        "value": 3000
+      },
+      {
+        "value": 3000
+      }
+    ],
+    "outputs": [
+      4000
+    ],
+    "expected": {
+      "fee": 2000,
+      "inputs": [
+        {
+          "i": 1,
+          "value": 3000
+        },
+        {
+          "i": 2,
+          "value": 3000
+        }
+      ],
+      "outputs": [
+        {
+          "value": 4000
+        }
+      ]
+    }
   }
 ]
 
diff --git a/utils.js b/utils.js
index 687fe66..af55a19 100644
--- a/utils.js
+++ b/utils.js
@@ -2,15 +2,29 @@
 var TX_EMPTY_SIZE = 4 + 1 + 1 + 4
 var TX_INPUT_BASE = 32 + 4 + 1 + 4
 var TX_INPUT_PUBKEYHASH = 107
+var TX_INPUT_SEGWIT = 27
+var TX_INPUT_TAPROOT = 17 // round up 16.5 bytes
 var TX_OUTPUT_BASE = 8 + 1
 var TX_OUTPUT_PUBKEYHASH = 25
+var TX_OUTPUT_SCRIPTHASH = 23
+var TX_OUTPUT_SEGWIT = 22
+var TX_OUTPUT_SEGWIT_SCRIPTHASH = 34
 
 function inputBytes (input) {
-  return TX_INPUT_BASE + (input.script ? input.script.length : TX_INPUT_PUBKEYHASH)
+  return TX_INPUT_BASE + (input.redeemScript ? input.redeemScript.length : 0) +
+    (input.witnessScript ? parseInt(input.witnessScript.length / 4)
+      : input.isTaproot ? TX_INPUT_TAPROOT
+        : input.witnessUtxo ? TX_INPUT_SEGWIT
+          : !input.redeemScript ? TX_INPUT_PUBKEYHASH : 0)
 }
 
 function outputBytes (output) {
-  return TX_OUTPUT_BASE + (output.script ? output.script.length : TX_OUTPUT_PUBKEYHASH)
+  return TX_OUTPUT_BASE + (output.script ? output.script.length
+    : output.address?.startsWith('bc1') || output.address?.startsWith('tb1')
+      ? output.address?.length === 42 ? TX_OUTPUT_SEGWIT : TX_OUTPUT_SEGWIT_SCRIPTHASH
+      : output.address?.startsWith('3') || output.address?.startsWith('2')
+        ? TX_OUTPUT_SCRIPTHASH : TX_OUTPUT_PUBKEYHASH
+  )
 }
 
 function dustThreshold (output, feeRate) {