diff --git a/blockchain/chain_test.go b/blockchain/chain_test.go
index f445f183..eec13960 100644
--- a/blockchain/chain_test.go
+++ b/blockchain/chain_test.go
@@ -10,6 +10,7 @@ import (
 	"github.com/btcsuite/btcd/blockchain"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 )
 
@@ -111,3 +112,370 @@ func TestHaveBlock(t *testing.T) {
 		}
 	}
 }
+
+// TestCalcSequenceLock tests the LockTimeToSequence function, and the
+// CalcSequenceLock method of a Chain instance. The tests exercise several
+// combinations of inputs to the CalcSequenceLock function in order to ensure
+// the returned SequenceLocks are correct for each test instance.
+func TestCalcSequenceLock(t *testing.T) {
+	fileName := "blk_0_to_4.dat.bz2"
+	blockTmp, err := loadBlocks(fileName)
+	if err != nil {
+		t.Errorf("Error loading file: %v\n", err)
+		return
+	}
+	var blocks []*btcutil.Block
+	for _, block := range blockTmp {
+		blocks = append(blocks, block)
+	}
+
+	// Create a new database and chain instance to run tests against.
+	chain, teardownFunc, err := chainSetup("haveblock", &chaincfg.MainNetParams)
+	if err != nil {
+		t.Errorf("Failed to setup chain instance: %v", err)
+		return
+	}
+	defer teardownFunc()
+
+	// Since we're not dealing with the real block chain, disable
+	// checkpoints and set the coinbase maturity to 1.
+	chain.DisableCheckpoints(true)
+	chain.TstSetCoinbaseMaturity(1)
+
+	// Load all the blocks into our test chain.
+	for i := 1; i < len(blocks); i++ {
+		_, isOrphan, err := chain.ProcessBlock(blocks[i], blockchain.BFNone)
+		if err != nil {
+			t.Errorf("ProcessBlock fail on block %v: %v\n", i, err)
+			return
+		}
+		if isOrphan {
+			t.Errorf("ProcessBlock incorrectly returned block %v "+
+				"is an orphan\n", i)
+			return
+		}
+	}
+
+	// Create with all the utxos within the create created above.
+	utxoView := blockchain.NewUtxoViewpoint()
+	for blockHeight, block := range blocks {
+		for _, tx := range block.Transactions() {
+			utxoView.AddTxOuts(tx, int32(blockHeight))
+		}
+	}
+	utxoView.SetBestHash(blocks[len(blocks)-1].Hash())
+
+	// The median past time from the point of view of the second to last
+	// block in the chain.
+	medianTime := blocks[2].MsgBlock().Header.Timestamp.Unix()
+
+	// The median past time of the *next* block will be the timestamp of
+	// the 2nd block due to the way MTP is calculated in order to be
+	// compatible with Bitcoin Core.
+	nextMedianTime := blocks[2].MsgBlock().Header.Timestamp.Unix()
+
+	// We'll refer to this utxo within each input in the transactions
+	// created below. This block that includes this UTXO has a height of 4.
+	targetTx := blocks[4].Transactions()[0]
+	utxo := wire.OutPoint{
+		Hash:  *targetTx.Hash(),
+		Index: 0,
+	}
+
+	// Add an additional transaction which will serve as our unconfirmed
+	// output.
+	var fakeScript []byte
+	unConfTx := &wire.MsgTx{
+		TxOut: []*wire.TxOut{
+			&wire.TxOut{
+				PkScript: fakeScript,
+				Value:    5,
+			},
+		},
+	}
+	unConfUtxo := wire.OutPoint{
+		Hash:  unConfTx.TxHash(),
+		Index: 0,
+	}
+	// Adding a utxo with a height of 0x7fffffff indicates that the output
+	// is currently unmined.
+	utxoView.AddTxOuts(btcutil.NewTx(unConfTx), 0x7fffffff)
+
+	tests := []struct {
+		tx   *btcutil.Tx
+		view *blockchain.UtxoViewpoint
+
+		want *blockchain.SequenceLock
+
+		mempool bool
+	}{
+		// A transaction of version one should disable sequence locks
+		// as the new sequence number semantics only apply to
+		// transactions version 2 or higher.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 1,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 3),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     -1,
+				BlockHeight: -1,
+			},
+		},
+		// A transaction with a single input, that a max int sequence
+		// number. This sequence number has the high bit set, so
+		// sequence locks should be disabled.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         wire.MaxTxInSequenceNum,
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     -1,
+				BlockHeight: -1,
+			},
+		},
+		// A transaction with a single input whose lock time is
+		// expressed in seconds. However, the specified lock time is
+		// below the required floor for time based lock times since
+		// they have time granularity of 512 seconds. As a result, the
+		// seconds lock-time should be just before the median time of
+		// the targeted block.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 2),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     medianTime - 1,
+				BlockHeight: -1,
+			},
+		},
+		// A transaction with a single input whose lock time is
+		// expressed in seconds. The number of seconds should be 1023
+		// seconds after the median past time of the last block in the
+		// chain.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 1024),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     medianTime + 1023,
+				BlockHeight: -1,
+			},
+		},
+		// A transaction with multiple inputs. The first input has a
+		// sequence lock in blocks with a value of 4. The last input
+		// has a sequence number with a value of 5, but has the disable
+		// bit set. So the first lock should be selected as it's the
+		// target lock as its the furthest in the future lock that
+		// isn't disabled.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 2560),
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence: blockchain.LockTimeToSequence(false, 3) |
+							wire.SequenceLockTimeDisabled,
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 3),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     medianTime + (5 << wire.SequenceLockTimeGranularity) - 1,
+				BlockHeight: 6,
+			},
+		},
+		// Transaction has a single input spending the genesis block
+		// transaction. The input's sequence number is encodes a
+		// relative lock-time in blocks (3 blocks). The sequence lock
+		// should have a value of -1 for seconds, but a block height of
+		// 6 meaning it can be included at height 7.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 3),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     -1,
+				BlockHeight: 6,
+			},
+		},
+		// A transaction with two inputs with lock times expressed in
+		// seconds. The selected sequence lock value for seconds should
+		// be the time further in the future.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 5120),
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 2560),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     medianTime + (10 << wire.SequenceLockTimeGranularity) - 1,
+				BlockHeight: -1,
+			},
+		},
+		// A transaction with two inputs with lock times expressed in
+		// seconds. The selected sequence lock value for blocks should
+		// be the height further in the future, so a height of 10
+		// indicating in can be included at height 7.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 1),
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 7),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     -1,
+				BlockHeight: 10,
+			},
+		},
+		// A transaction with multiple inputs. Two inputs are time
+		// based, and the other two are input maturity based. The lock
+		// lying further into the future for both inputs should be
+		// chosen.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 2560),
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 6656),
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 3),
+					},
+					&wire.TxIn{
+						PreviousOutPoint: utxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 9),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     medianTime + (13 << wire.SequenceLockTimeGranularity) - 1,
+				BlockHeight: 12,
+			},
+		},
+		// A transaction with a single unconfirmed input. As the input
+		// is confirmed, the height of the input should be interpreted
+		// as the height of the *next* block. So the relative block
+		// lock should be based from a height of 5 rather than a height
+		// of 4.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: unConfUtxo,
+						Sequence:         blockchain.LockTimeToSequence(false, 2),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     -1,
+				BlockHeight: 6,
+			},
+		},
+		// A transaction with a single unconfirmed input. The input has
+		// a time based lock, so the lock time should be based off the
+		// MTP of the *next* block.
+		{
+			tx: btcutil.NewTx(&wire.MsgTx{
+				Version: 2,
+				TxIn: []*wire.TxIn{
+					&wire.TxIn{
+						PreviousOutPoint: unConfUtxo,
+						Sequence:         blockchain.LockTimeToSequence(true, 1024),
+					},
+				},
+			}),
+			view: utxoView,
+			want: &blockchain.SequenceLock{
+				Seconds:     nextMedianTime + 1023,
+				BlockHeight: -1,
+			},
+		},
+	}
+
+	t.Logf("Running %v SequenceLock tests", len(tests))
+	for i, test := range tests {
+		seqLock, err := chain.CalcSequenceLock(test.tx, test.view, test.mempool)
+		if err != nil {
+			t.Fatalf("test #%d, unable to calc sequence lock: %v", i, err)
+		}
+
+		if seqLock.Seconds != test.want.Seconds {
+			t.Fatalf("test #%d got %v seconds want %v seconds",
+				i, seqLock.Seconds, test.want.Seconds)
+		}
+		if seqLock.BlockHeight != test.want.BlockHeight {
+			t.Fatalf("test #%d got height of %v want height of %v ",
+				i, seqLock.BlockHeight, test.want.BlockHeight)
+		}
+	}
+}