diff --git a/src/bench/mempool_eviction.cpp b/src/bench/mempool_eviction.cpp
index e118fca314..22e82b4ad2 100644
--- a/src/bench/mempool_eviction.cpp
+++ b/src/bench/mempool_eviction.cpp
@@ -21,7 +21,7 @@ static void AddTx(const CTransactionRef& tx, const CAmount& nFee, CTxMemPool& po
     pool.addUnchecked(CTxMemPoolEntry(
         tx, nFee, nTime, dPriority, nHeight, sequence,
         tx->GetValueOut(),
-        spendsCoinbase, sigOpCost, lp));
+        spendsCoinbase, /*extra_weight=*/0, sigOpCost, lp));
 }
 
 // Right now this is only testing eviction performance in an extremely small
diff --git a/src/bench/mempool_stress.cpp b/src/bench/mempool_stress.cpp
index 814c3032ef..c1b89f1fe2 100644
--- a/src/bench/mempool_stress.cpp
+++ b/src/bench/mempool_stress.cpp
@@ -22,7 +22,7 @@ static void AddTx(const CTransactionRef& tx, CTxMemPool& pool) EXCLUSIVE_LOCKS_R
     bool spendsCoinbase = false;
     unsigned int sigOpCost = 4;
     LockPoints lp;
-    pool.addUnchecked(CTxMemPoolEntry(tx, 1000, nTime, nHeight, sequence, /*entry_tx_inputs_coin_age=*/coin_age, tx->GetValueOut(), spendsCoinbase, sigOpCost, lp));
+    pool.addUnchecked(CTxMemPoolEntry(tx, 1000, nTime, nHeight, sequence, /*entry_tx_inputs_coin_age=*/coin_age, tx->GetValueOut(), spendsCoinbase, /*extra_weight=*/0, sigOpCost, lp));
 }
 
 struct Available {
diff --git a/src/bench/rpc_mempool.cpp b/src/bench/rpc_mempool.cpp
index 8eb83c4853..5cd86fa848 100644
--- a/src/bench/rpc_mempool.cpp
+++ b/src/bench/rpc_mempool.cpp
@@ -17,7 +17,7 @@
 static void AddTx(const CTransactionRef& tx, const CAmount& fee, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
 {
     LockPoints lp;
-    pool.addUnchecked(CTxMemPoolEntry(tx, fee, /*time=*/0, /*entry_height=*/0, /*entry_sequence=*/0, /*entry_tx_inputs_coin_age=*/0.0, /*in_chain_input_value=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
+    pool.addUnchecked(CTxMemPoolEntry(tx, fee, /*time=*/0, /*entry_height=*/0, /*entry_sequence=*/0, /*entry_tx_inputs_coin_age=*/0.0, /*in_chain_input_value=*/0, /*spends_coinbase=*/false, /*extra_weight=*/0, /*sigops_cost=*/4, lp));
 }
 
 static void RpcMempool(benchmark::Bench& bench)
diff --git a/src/common/args.cpp b/src/common/args.cpp
index 86a71fece1..2bb3f141d7 100644
--- a/src/common/args.cpp
+++ b/src/common/args.cpp
@@ -507,6 +507,25 @@ int64_t SettingToInt(const common::SettingsValue& value, int64_t nDefault)
     return SettingToInt(value).value_or(nDefault);
 }
 
+std::optional<int64_t> ArgsManager::GetFixedPointArg(const std::string& arg, int decimals) const
+{
+    const common::SettingsValue value = GetSetting(arg);
+    return SettingToFixedPoint(value, decimals);
+}
+
+std::optional<int64_t> SettingToFixedPoint(const common::SettingsValue& value, int decimals)
+{
+    if (value.isNull()) return std::nullopt;
+    if (value.isFalse()) return 0;
+    if (value.isTrue()) return 1;
+    if (!value.isNum()) value.get_str();  // throws an exception if type is wrong
+    int64_t v;
+    if (!ParseFixedPoint(value.getValStr(), decimals, &v)) {
+        throw std::runtime_error(strprintf("Parse error ('%s')", value.getValStr()));
+    }
+    return v;
+}
+
 bool ArgsManager::GetBoolArg(const std::string& strArg, bool fDefault) const
 {
     return GetBoolArg(strArg).value_or(fDefault);
diff --git a/src/common/args.h b/src/common/args.h
index 1495e20f09..66e2c39460 100644
--- a/src/common/args.h
+++ b/src/common/args.h
@@ -92,6 +92,8 @@ std::optional<std::string> SettingToString(const common::SettingsValue&);
 int64_t SettingToInt(const common::SettingsValue&, int64_t);
 std::optional<int64_t> SettingToInt(const common::SettingsValue&);
 
+std::optional<int64_t> SettingToFixedPoint(const common::SettingsValue&, int decimals);
+
 bool SettingToBool(const common::SettingsValue&, bool);
 std::optional<bool> SettingToBool(const common::SettingsValue&);
 
@@ -305,6 +307,15 @@ protected:
     int64_t GetIntArg(const std::string& strArg, int64_t nDefault) const;
     std::optional<int64_t> GetIntArg(const std::string& strArg) const;
 
+    /**
+     * Return fixed-point argument
+     *
+     * @param arg Argument to get (e.g. "-foo")
+     * @param decimals Number of fractional decimal digits to accept
+     * @return Command-line argument (0 if invalid number) multiplied by 10**decimals
+     */
+    std::optional<int64_t> GetFixedPointArg(const std::string& arg, int decimals) const;
+
     /**
      * Return boolean argument or default value
      *
diff --git a/src/init.cpp b/src/init.cpp
index cbbf6ed08d..cd767271ca 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -680,6 +680,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-bytespersigop", strprintf("Equivalent bytes per sigop in transactions for relay and mining (default: %u)", DEFAULT_BYTES_PER_SIGOP), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-bytespersigopstrict", strprintf("Minimum bytes per sigop in transactions we relay and mine (default: %u)", DEFAULT_BYTES_PER_SIGOP_STRICT), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarrier", strprintf("Relay and mine data carrier transactions (default: %u)", DEFAULT_ACCEPT_DATACARRIER), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    argsman.AddArg("-datacarriercost", strprintf("Treat extra data in transactions as at least N vbytes per actual byte (default: %s)", DEFAULT_WEIGHT_PER_DATA_BYTE / 4.0), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarrierfullcount", strprintf("Apply datacarriersize limit to all known datacarrier methods (default: %u)", DEFAULT_DATACARRIER_FULLCOUNT), ArgsManager::ALLOW_ANY | (DEFAULT_DATACARRIER_FULLCOUNT ? uint32_t{ArgsManager::DEBUG_ONLY} : 0), OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarriersize",
                    strprintf("Maximum size of data in data carrier transactions we relay and mine, in bytes (default: %u)",
@@ -1087,6 +1088,10 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         }
     }
 
+    if (auto parsed = args.GetFixedPointArg("-datacarriercost", 2)) {
+        g_weight_per_data_byte = ((*parsed * WITNESS_SCALE_FACTOR) + 99) / 100;
+    }
+
     nBytesPerSigOp = args.GetIntArg("-bytespersigop", nBytesPerSigOp);
     nBytesPerSigOpStrict = args.GetIntArg("-bytespersigopstrict", nBytesPerSigOpStrict);
 
diff --git a/src/kernel/mempool_entry.h b/src/kernel/mempool_entry.h
index ff32f52b5c..19030235b1 100644
--- a/src/kernel/mempool_entry.h
+++ b/src/kernel/mempool_entry.h
@@ -96,6 +96,7 @@ private:
     const int64_t nTime;            //!< Local time when entering the mempool
     const uint64_t entry_sequence;  //!< Sequence number used to determine whether this transaction is too recent for relay
     const int64_t sigOpCost;        //!< Total sigop cost
+    const int32_t m_extra_weight;   //!< Policy-only additional transaction weight beyond nTxWeight
     const size_t nModSize;          //!< Cached modified size for priority
     const double entryPriority;     //!< Priority when entering the mempool
     const unsigned int entryHeight; //!< Chain height when entering the mempool
@@ -127,6 +128,7 @@ public:
                     double entry_tx_inputs_coin_age,
                     CAmount in_chain_input_value,
                     bool spends_coinbase,
+                    int32_t extra_weight,
                     int64_t sigops_cost, LockPoints lp)
         : tx{tx},
           nFee{fee},
@@ -135,6 +137,7 @@ public:
           nTime{time},
           entry_sequence{entry_sequence},
           sigOpCost{sigops_cost},
+          m_extra_weight{extra_weight},
           nModSize{CalculateModifiedSize(*tx, GetTxSize())},
           entryPriority{ComputePriority2(entry_tx_inputs_coin_age, nModSize)},
           entryHeight{entry_height},
@@ -177,7 +180,7 @@ public:
     const CAmount& GetFee() const { return nFee; }
     int32_t GetTxSize() const
     {
-        return GetVirtualTransactionSize(nTxWeight, sigOpCost, ::nBytesPerSigOp);
+        return GetVirtualTransactionSize(nTxWeight + m_extra_weight, sigOpCost, ::nBytesPerSigOp);
     }
     int32_t GetTxWeight() const { return nTxWeight; }
     std::chrono::seconds GetTime() const { return std::chrono::seconds{nTime}; }
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index 6fc3962d9f..c7bafa2617 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -749,7 +749,7 @@ public:
     {
         if (!m_node.mempool) return {};
         LockPoints lp;
-        CTxMemPoolEntry entry(tx, 0, 0, 0, 0, 0, 0, false, 0, lp);
+        CTxMemPoolEntry entry(tx, 0, 0, 0, 0, 0, 0, false, /*extra_weight=*/0, 0, lp);
         LOCK(m_node.mempool->cs);
         return m_node.mempool->CheckPackageLimits({tx}, entry.GetTxSize());
     }
diff --git a/src/node/psbt.cpp b/src/node/psbt.cpp
index 51e252bffc..37b8bd02cc 100644
--- a/src/node/psbt.cpp
+++ b/src/node/psbt.cpp
@@ -5,6 +5,7 @@
 #include <coins.h>
 #include <consensus/amount.h>
 #include <consensus/tx_verify.h>
+#include <consensus/validation.h>
 #include <node/psbt.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
@@ -137,7 +138,7 @@ PSBTAnalysis AnalyzePSBT(PartiallySignedTransaction psbtx)
 
         if (success) {
             CTransaction ctx = CTransaction(mtx);
-            size_t size(GetVirtualTransactionSize(ctx, GetTransactionSigOpCost(ctx, view, STANDARD_SCRIPT_VERIFY_FLAGS), ::nBytesPerSigOp));
+            size_t size(GetVirtualTransactionSize(GetTransactionWeight(ctx) + CalculateExtraTxWeight(ctx, view, ::g_weight_per_data_byte), GetTransactionSigOpCost(ctx, view, STANDARD_SCRIPT_VERIFY_FLAGS), ::nBytesPerSigOp));
             result.estimated_vsize = size;
             // Estimate fee rate
             CFeeRate feerate(fee, size);
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index 8ef3a98830..74b5a76735 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -435,3 +435,26 @@ size_t DatacarrierBytes(const CTransaction& tx, const CCoinsViewCache& view)
 
     return ret;
 }
+
+int32_t CalculateExtraTxWeight(const CTransaction& tx, const CCoinsViewCache& view, const unsigned int weight_per_data_byte)
+{
+    int32_t mod_weight{0};
+
+    // Add in any extra weight for data bytes
+    if (weight_per_data_byte > 1) {
+        for (const CTxIn& txin : tx.vin) {
+            const CTxOut &utxo = view.AccessCoin(txin.prevout).out;
+            auto[script, consensus_weight_per_byte] = GetScriptForTransactionInput(utxo.scriptPubKey, txin);
+            if (weight_per_data_byte > consensus_weight_per_byte) {
+                mod_weight += script.DatacarrierBytes() * (weight_per_data_byte - consensus_weight_per_byte);
+            }
+        }
+        if (weight_per_data_byte > WITNESS_SCALE_FACTOR) {
+            for (const CTxOut& txout : tx.vout) {
+                mod_weight += txout.scriptPubKey.DatacarrierBytes() * (weight_per_data_byte - WITNESS_SCALE_FACTOR);
+            }
+        }
+    }
+
+    return mod_weight;
+}
diff --git a/src/policy/policy.h b/src/policy/policy.h
index dd563d8bda..a00d09a42e 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -48,6 +48,8 @@ static constexpr unsigned int DEFAULT_INCREMENTAL_RELAY_FEE{1000};
 static constexpr unsigned int DEFAULT_BYTES_PER_SIGOP{20};
 /** Default for -bytespersigopstrict */
 static constexpr unsigned int DEFAULT_BYTES_PER_SIGOP_STRICT{20};
+/** Default for -datacarriercost (multiplied by WITNESS_SCALE_FACTOR) */
+static constexpr unsigned int DEFAULT_WEIGHT_PER_DATA_BYTE{1};
 /** Default for -permitbarepubkey */
 static constexpr bool DEFAULT_PERMIT_BAREPUBKEY{true};
 /** Default for -permitbaremultisig */
@@ -201,4 +203,6 @@ std::pair<CScript, unsigned int> GetScriptForTransactionInput(CScript prevScript
 
 size_t DatacarrierBytes(const CTransaction& tx, const CCoinsViewCache& view);
 
+int32_t CalculateExtraTxWeight(const CTransaction& tx, const CCoinsViewCache& view, const unsigned int weight_per_data_byte);
+
 #endif // BITCOIN_POLICY_POLICY_H
diff --git a/src/policy/settings.cpp b/src/policy/settings.cpp
index 6200b4bd30..a202a9495c 100644
--- a/src/policy/settings.cpp
+++ b/src/policy/settings.cpp
@@ -9,3 +9,4 @@
 
 unsigned int nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;
 unsigned int nBytesPerSigOpStrict = DEFAULT_BYTES_PER_SIGOP_STRICT;
+unsigned int g_weight_per_data_byte = DEFAULT_WEIGHT_PER_DATA_BYTE;
diff --git a/src/policy/settings.h b/src/policy/settings.h
index 14fb9b769b..47ea346283 100644
--- a/src/policy/settings.h
+++ b/src/policy/settings.h
@@ -8,5 +8,6 @@
 
 extern unsigned int nBytesPerSigOp;
 extern unsigned int nBytesPerSigOpStrict;
+extern unsigned int g_weight_per_data_byte;
 
 #endif // BITCOIN_POLICY_SETTINGS_H
diff --git a/src/test/fuzz/util/mempool.cpp b/src/test/fuzz/util/mempool.cpp
index a648da19f2..3dfa3d6e94 100644
--- a/src/test/fuzz/util/mempool.cpp
+++ b/src/test/fuzz/util/mempool.cpp
@@ -38,6 +38,7 @@ CTxMemPoolEntry ConsumeTxMemPoolEntry(FuzzedDataProvider& fuzzed_data_provider,
     const double coin_age = fuzzed_data_provider.ConsumeFloatingPoint<double>();
     const unsigned int entry_height = fuzzed_data_provider.ConsumeIntegralInRange<unsigned int>(0, std::numeric_limits<unsigned int>::max() - 1);
     const bool spends_coinbase = fuzzed_data_provider.ConsumeBool();
+    const int32_t extra_weight = fuzzed_data_provider.ConsumeIntegralInRange<int32_t>(0, GetTransactionWeight(tx) * 3);
     const unsigned int sig_op_cost = fuzzed_data_provider.ConsumeIntegralInRange<unsigned int>(0, MAX_BLOCK_SIGOPS_COST);
-    return CTxMemPoolEntry{MakeTransactionRef(tx), fee, time, entry_height, entry_sequence, /*entry_tx_inputs_coin_age=*/coin_age, tx.GetValueOut(), spends_coinbase, sig_op_cost, {}};
+    return CTxMemPoolEntry{MakeTransactionRef(tx), fee, time, entry_height, entry_sequence, /*entry_tx_inputs_coin_age=*/coin_age, tx.GetValueOut(), spends_coinbase, extra_weight, sig_op_cost, {}};
 }
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index 053540098d..29d84059f8 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -566,7 +566,7 @@ std::vector<CTransactionRef> TestChain100Setup::PopulateMempool(FastRandomContex
                                                          /*time=*/0, /*entry_height=*/ height, /*entry_sequence=*/0,
                                                          /*entry_tx_inputs_coin_age=*/coin_age,
                                                          in_chain_input_value,
-                                                         /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
+                                                         /*spends_coinbase=*/false, /*extra_weight=*/0, /*sigops_cost=*/4, lp));
         }
         --num_transactions;
     }
@@ -598,7 +598,7 @@ void TestChain100Setup::MockMempoolMinFee(const CFeeRate& target_feerate)
                                                  /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0,
                                                  /*entry_tx_inputs_coin_age=*/0.0,
                                                  /*in_chain_input_value=*/0,
-                                                 /*spends_coinbase=*/true, /*sigops_cost=*/1, lp));
+                                                 /*spends_coinbase=*/true, /*extra_weight=*/0, /*sigops_cost=*/1, lp));
     m_node.mempool->TrimToSize(0);
     assert(m_node.mempool->GetMinFee() == target_feerate);
 }
diff --git a/src/test/util/txmempool.cpp b/src/test/util/txmempool.cpp
index d018b53ae5..9ee5fd1ae0 100644
--- a/src/test/util/txmempool.cpp
+++ b/src/test/util/txmempool.cpp
@@ -39,7 +39,7 @@ CTxMemPoolEntry TestMemPoolEntryHelper::FromTx(const CTransactionRef& tx) const
 {
     constexpr double coin_age{0};
     const CAmount inChainValue = 0;
-    return CTxMemPoolEntry{tx, nFee, TicksSinceEpoch<std::chrono::seconds>(time), nHeight, m_sequence, /*entry_tx_inputs_coin_age=*/coin_age, inChainValue, spendsCoinbase, sigOpCost, lp};
+    return CTxMemPoolEntry{tx, nFee, TicksSinceEpoch<std::chrono::seconds>(time), nHeight, m_sequence, /*entry_tx_inputs_coin_age=*/coin_age, inChainValue, spendsCoinbase, /*extra_weight=*/0, sigOpCost, lp};
 }
 
 std::optional<std::string> CheckPackageMempoolAcceptResult(const Package& txns,
diff --git a/src/validation.cpp b/src/validation.cpp
index 6f253e32d4..8f4d526b62 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1048,10 +1048,11 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     // Set entry_sequence to 0 when rejectmsg_zero_mempool_entry_seq is used; this allows txs from a block
     // reorg to be marked earlier than any child txs that were already in the mempool.
     const uint64_t entry_sequence = args.m_ignore_rejects.count(rejectmsg_zero_mempool_entry_seq) ? 0 : m_pool.GetSequence();
+    int32_t extra_weight = CalculateExtraTxWeight(*ptx, m_view, ::g_weight_per_data_byte);
     entry.reset(new CTxMemPoolEntry(ptx, ws.m_base_fees, nAcceptTime, m_active_chainstate.m_chain.Height(), entry_sequence,
                                     /*entry_tx_inputs_coin_age=*/coin_age,
                                     inChainInputValue,
-                                    fSpendsCoinbase, nSigOpsCost, lock_points.value()));
+                                    fSpendsCoinbase, extra_weight, nSigOpsCost, lock_points.value()));
     ws.m_vsize = entry->GetTxSize();
     entry->mapSPK = mapSPK;
 
diff --git a/test/lint/check-doc.py b/test/lint/check-doc.py
index f55d0f8cb7..8696ca8e0e 100755
--- a/test/lint/check-doc.py
+++ b/test/lint/check-doc.py
@@ -15,7 +15,7 @@ import re
 
 FOLDER_GREP = 'src'
 FOLDER_TEST = 'src/test/'
-REGEX_ARG = r'\b(?:GetArg|GetArgs|GetBoolArg|GetIntArg|GetPathArg|IsArgSet|get_net)\("(-[^"]+)"'
+REGEX_ARG = r'\b(?:GetArg|GetArgs|GetBoolArg|GetIntArg|GetFixedPointArg|GetPathArg|IsArgSet|get_net)\("(-[^"]+)"'
 REGEX_DOC = r'AddArg\("(-[^"=]+?)(?:=|")'
 CMD_ROOT_DIR = '$(git rev-parse --show-toplevel)/{}'.format(FOLDER_GREP)
 CMD_GREP_ARGS = r"git grep --perl-regexp '{}' -- {} ':(exclude){}'".format(REGEX_ARG, CMD_ROOT_DIR, FOLDER_TEST)