diff --git a/src/block.js b/src/block.js
index 22449fd..8ec6c29 100644
--- a/src/block.js
+++ b/src/block.js
@@ -127,12 +127,17 @@ class Block {
   hasWitness() {
     return anyTxHasWitness(this.transactions);
   }
-  byteLength(headersOnly) {
+  weight() {
+    const base = this.byteLength(false, false);
+    const total = this.byteLength(false, true);
+    return base * 3 + total;
+  }
+  byteLength(headersOnly, allowWitness = true) {
     if (headersOnly || !this.transactions) return 80;
     return (
       80 +
       varuint.encodingLength(this.transactions.length) +
-      this.transactions.reduce((a, x) => a + x.byteLength(), 0)
+      this.transactions.reduce((a, x) => a + x.byteLength(allowWitness), 0)
     );
   }
   getHash() {
diff --git a/src/transaction.js b/src/transaction.js
index c4e6506..e2d6a6b 100644
--- a/src/transaction.js
+++ b/src/transaction.js
@@ -179,15 +179,31 @@ class Transaction {
     });
   }
   weight() {
-    const base = this.__byteLength(false);
-    const total = this.__byteLength(true);
+    const base = this.byteLength(false);
+    const total = this.byteLength(true);
     return base * 3 + total;
   }
   virtualSize() {
     return Math.ceil(this.weight() / 4);
   }
-  byteLength() {
-    return this.__byteLength(true);
+  byteLength(_ALLOW_WITNESS = true) {
+    const hasWitnesses = _ALLOW_WITNESS && this.hasWitnesses();
+    return (
+      (hasWitnesses ? 10 : 8) +
+      varuint.encodingLength(this.ins.length) +
+      varuint.encodingLength(this.outs.length) +
+      this.ins.reduce((sum, input) => {
+        return sum + 40 + varSliceSize(input.script);
+      }, 0) +
+      this.outs.reduce((sum, output) => {
+        return sum + 8 + varSliceSize(output.script);
+      }, 0) +
+      (hasWitnesses
+        ? this.ins.reduce((sum, input) => {
+            return sum + vectorSize(input.witness);
+          }, 0)
+        : 0)
+    );
   }
   clone() {
     const newTx = new Transaction();
@@ -269,7 +285,7 @@ class Transaction {
       txTmp.ins[inIndex].script = ourScript;
     }
     // serialize and hash
-    const buffer = Buffer.allocUnsafe(txTmp.__byteLength(false) + 4);
+    const buffer = Buffer.allocUnsafe(txTmp.byteLength(false) + 4);
     buffer.writeInt32LE(hashType, buffer.length - 4);
     txTmp.__toBuffer(buffer, 0, false);
     return bcrypto.hash256(buffer);
@@ -386,27 +402,8 @@ class Transaction {
     typeforce(types.tuple(types.Number, [types.Buffer]), arguments);
     this.ins[index].witness = witness;
   }
-  __byteLength(_ALLOW_WITNESS) {
-    const hasWitnesses = _ALLOW_WITNESS && this.hasWitnesses();
-    return (
-      (hasWitnesses ? 10 : 8) +
-      varuint.encodingLength(this.ins.length) +
-      varuint.encodingLength(this.outs.length) +
-      this.ins.reduce((sum, input) => {
-        return sum + 40 + varSliceSize(input.script);
-      }, 0) +
-      this.outs.reduce((sum, output) => {
-        return sum + 8 + varSliceSize(output.script);
-      }, 0) +
-      (hasWitnesses
-        ? this.ins.reduce((sum, input) => {
-            return sum + vectorSize(input.witness);
-          }, 0)
-        : 0)
-    );
-  }
-  __toBuffer(buffer, initialOffset, _ALLOW_WITNESS) {
-    if (!buffer) buffer = Buffer.allocUnsafe(this.__byteLength(_ALLOW_WITNESS));
+  __toBuffer(buffer, initialOffset, _ALLOW_WITNESS = false) {
+    if (!buffer) buffer = Buffer.allocUnsafe(this.byteLength(_ALLOW_WITNESS));
     let offset = initialOffset || 0;
     function writeSlice(slice) {
       offset += slice.copy(buffer, offset);
diff --git a/test/block.spec.ts b/test/block.spec.ts
index 0f74392..e93420c 100644
--- a/test/block.spec.ts
+++ b/test/block.spec.ts
@@ -48,6 +48,11 @@ describe('Block', () => {
         assert.strictEqual(block.bits, f.bits);
         assert.strictEqual(block.nonce, f.nonce);
         assert.strictEqual(!block.transactions, f.hex.length === 160);
+        if (f.size && f.strippedSize && f.weight) {
+          assert.strictEqual(block.byteLength(false, true), f.size);
+          assert.strictEqual(block.byteLength(false, false), f.strippedSize);
+          assert.strictEqual(block.weight(), f.weight);
+        }
       });
     });
 
diff --git a/test/fixtures/block.json b/test/fixtures/block.json
index c60685e..8ea521c 100644
--- a/test/fixtures/block.json
+++ b/test/fixtures/block.json
@@ -133,7 +133,10 @@
       "prevHash": "8980ebb11236bacc66c447d5ad961bc546c0f9cc385a08000000000000000000",
       "timestamp": 1537429727,
       "valid": true,
-      "version": 536870912
+      "version": 536870912,
+      "size": 2355,
+      "strippedSize": 2209,
+      "weight": 8982
     }
   ],
   "invalid": [
diff --git a/ts_src/block.ts b/ts_src/block.ts
index cf4ed51..9a4d675 100644
--- a/ts_src/block.ts
+++ b/ts_src/block.ts
@@ -148,13 +148,19 @@ export class Block {
     return anyTxHasWitness(this.transactions!);
   }
 
-  byteLength(headersOnly?: boolean): number {
+  weight(): number {
+    const base = this.byteLength(false, false);
+    const total = this.byteLength(false, true);
+    return base * 3 + total;
+  }
+
+  byteLength(headersOnly?: boolean, allowWitness: boolean = true): number {
     if (headersOnly || !this.transactions) return 80;
 
     return (
       80 +
       varuint.encodingLength(this.transactions.length) +
-      this.transactions.reduce((a, x) => a + x.byteLength(), 0)
+      this.transactions.reduce((a, x) => a + x.byteLength(allowWitness), 0)
     );
   }
 
diff --git a/ts_src/transaction.ts b/ts_src/transaction.ts
index 0419ba2..88e9242 100644
--- a/ts_src/transaction.ts
+++ b/ts_src/transaction.ts
@@ -237,8 +237,8 @@ export class Transaction {
   }
 
   weight(): number {
-    const base = this.__byteLength(false);
-    const total = this.__byteLength(true);
+    const base = this.byteLength(false);
+    const total = this.byteLength(true);
     return base * 3 + total;
   }
 
@@ -246,8 +246,25 @@ export class Transaction {
     return Math.ceil(this.weight() / 4);
   }
 
-  byteLength(): number {
-    return this.__byteLength(true);
+  byteLength(_ALLOW_WITNESS: boolean = true): number {
+    const hasWitnesses = _ALLOW_WITNESS && this.hasWitnesses();
+
+    return (
+      (hasWitnesses ? 10 : 8) +
+      varuint.encodingLength(this.ins.length) +
+      varuint.encodingLength(this.outs.length) +
+      this.ins.reduce((sum, input) => {
+        return sum + 40 + varSliceSize(input.script);
+      }, 0) +
+      this.outs.reduce((sum, output) => {
+        return sum + 8 + varSliceSize(output.script);
+      }, 0) +
+      (hasWitnesses
+        ? this.ins.reduce((sum, input) => {
+            return sum + vectorSize(input.witness);
+          }, 0)
+        : 0)
+    );
   }
 
   clone(): Transaction {
@@ -352,7 +369,7 @@ export class Transaction {
     }
 
     // serialize and hash
-    const buffer: Buffer = Buffer.allocUnsafe(txTmp.__byteLength(false) + 4);
+    const buffer: Buffer = Buffer.allocUnsafe(txTmp.byteLength(false) + 4);
     buffer.writeInt32LE(hashType, buffer.length - 4);
     txTmp.__toBuffer(buffer, 0, false);
 
@@ -506,34 +523,13 @@ export class Transaction {
     this.ins[index].witness = witness;
   }
 
-  private __byteLength(_ALLOW_WITNESS: boolean): number {
-    const hasWitnesses = _ALLOW_WITNESS && this.hasWitnesses();
-
-    return (
-      (hasWitnesses ? 10 : 8) +
-      varuint.encodingLength(this.ins.length) +
-      varuint.encodingLength(this.outs.length) +
-      this.ins.reduce((sum, input) => {
-        return sum + 40 + varSliceSize(input.script);
-      }, 0) +
-      this.outs.reduce((sum, output) => {
-        return sum + 8 + varSliceSize(output.script);
-      }, 0) +
-      (hasWitnesses
-        ? this.ins.reduce((sum, input) => {
-            return sum + vectorSize(input.witness);
-          }, 0)
-        : 0)
-    );
-  }
-
   private __toBuffer(
     buffer?: Buffer,
     initialOffset?: number,
-    _ALLOW_WITNESS?: boolean,
+    _ALLOW_WITNESS: boolean = false,
   ): Buffer {
     if (!buffer)
-      buffer = Buffer.allocUnsafe(this.__byteLength(_ALLOW_WITNESS!)) as Buffer;
+      buffer = Buffer.allocUnsafe(this.byteLength(_ALLOW_WITNESS)) as Buffer;
 
     let offset = initialOffset || 0;
 
diff --git a/types/block.d.ts b/types/block.d.ts
index d77bb1b..7d8309c 100644
--- a/types/block.d.ts
+++ b/types/block.d.ts
@@ -15,7 +15,8 @@ export declare class Block {
     getWitnessCommit(): Buffer | null;
     hasWitnessCommit(): boolean;
     hasWitness(): boolean;
-    byteLength(headersOnly?: boolean): number;
+    weight(): number;
+    byteLength(headersOnly?: boolean, allowWitness?: boolean): number;
     getHash(): Buffer;
     getId(): string;
     getUTCDate(): Date;
diff --git a/types/transaction.d.ts b/types/transaction.d.ts
index f0db04e..6846ea5 100644
--- a/types/transaction.d.ts
+++ b/types/transaction.d.ts
@@ -30,7 +30,7 @@ export declare class Transaction {
     hasWitnesses(): boolean;
     weight(): number;
     virtualSize(): number;
-    byteLength(): number;
+    byteLength(_ALLOW_WITNESS?: boolean): number;
     clone(): Transaction;
     /**
      * Hash transaction for signing a specific input.
@@ -48,6 +48,5 @@ export declare class Transaction {
     toHex(): string;
     setInputScript(index: number, scriptSig: Buffer): void;
     setWitness(index: number, witness: Buffer[]): void;
-    private __byteLength;
     private __toBuffer;
 }