diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -264,14 +264,6 @@
     // GetValueIn() is a method on CCoinsViewCache, because
     // inputs must be known to compute value in.
 
-    // Compute priority, given priority of inputs and (optionally) tx size
-    double ComputePriority(double dPriorityInputs,
-                           unsigned int nTxSize = 0) const;
-
-    // Compute modified tx size for priority calculation (optionally given tx
-    // size)
-    unsigned int CalculateModifiedSize(unsigned int nTxSize = 0) const;
-
     /**
      * Get the total transaction size in bytes.
      * @return Total transaction size in bytes
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -83,36 +83,6 @@
     return nValueOut;
 }
 
-double CTransaction::ComputePriority(double dPriorityInputs,
-                                     unsigned int nTxSize) const {
-    nTxSize = CalculateModifiedSize(nTxSize);
-    if (nTxSize == 0) {
-        return 0.0;
-    }
-
-    return dPriorityInputs / nTxSize;
-}
-
-unsigned int CTransaction::CalculateModifiedSize(unsigned int nTxSize) const {
-    // In order to avoid disincentivizing cleaning up the UTXO set we don't
-    // count the constant overhead for each txin and up to 110 bytes of
-    // scriptSig (which is enough to cover a compressed pubkey p2sh redemption)
-    // for priority. Providing any more cleanup incentive than making additional
-    // inputs free would risk encouraging people to create junk outputs to
-    // redeem later.
-    if (nTxSize == 0) {
-        nTxSize = GetTotalSize();
-    }
-    for (const auto &nVin : vin) {
-        unsigned int offset =
-            41U + std::min(110U, (unsigned int)nVin.scriptSig.size());
-        if (nTxSize > offset) {
-            nTxSize -= offset;
-        }
-    }
-    return nTxSize;
-}
-
 unsigned int CTransaction::GetTotalSize() const {
     return ::GetSerializeSize(*this, PROTOCOL_VERSION);
 }
diff --git a/src/txmempool.h b/src/txmempool.h
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -71,8 +71,6 @@
     Amount nFee;
     //!< ... and avoid recomputing tx size
     size_t nTxSize;
-    //!< ... and modified size for priority
-    size_t nModSize;
     //!< ... and total memory usage
     size_t nUsageSize;
     //!< Local time when entering the mempool
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -33,7 +33,6 @@
       spendsCoinbase(_spendsCoinbase), sigOpCount(_sigOpsCount),
       lockPoints(lp) {
     nTxSize = tx->GetTotalSize();
-    nModSize = tx->CalculateModifiedSize(GetTxSize());
     nUsageSize = RecursiveDynamicUsage(tx);
 
     nCountWithDescendants = 1;