diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index 7d8ef6571..f3ee0fbe3 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -490,8 +490,6 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
         else nBytesInputs += 148;
     }
 
-    bool conservative_estimate = CalculateEstimateType(FeeEstimateMode::UNSET, coinControl->signalRbf);
-
     // calculation
     if (nQuantity > 0)
     {
@@ -583,12 +581,8 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
     QString toolTipDust = tr("This label turns red if any recipient receives an amount smaller than the current dust threshold.");
 
     // how many satoshis the estimated fee can vary per byte we guess wrong
-    double dFeeVary;
-    if (payTxFee.GetFeePerK() > 0)
-        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), payTxFee.GetFeePerK()) / 1000;
-    else {
-        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), ::feeEstimator.estimateSmartFee(*coinControl->m_confirm_target, NULL, ::mempool, conservative_estimate).GetFeePerK()) / 1000;
-    }
+    double dFeeVary = (double)nPayFee / nBytes;
+
     QString toolTip4 = tr("Can vary +/- %1 satoshi(s) per input.").arg(dFeeVary);
 
     l3->setToolTip(toolTip4);
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index d48b3753b..a01886c3e 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -652,7 +652,7 @@ void SendCoinsDialog::updateCoinControlState(CCoinControl& ctrl)
     if (ui->radioCustomFee->isChecked()) {
         ctrl.m_feerate = CFeeRate(ui->customFee->value());
     } else {
-        ctrl.m_feerate = boost::none;
+        ctrl.m_feerate.reset();
     }
     // Avoid using global defaults when sending money from the GUI
     // Either custom fee will be used or if not selected, the confirmation target from dropdown box
@@ -666,15 +666,13 @@ void SendCoinsDialog::updateSmartFeeLabel()
         return;
     CCoinControl coin_control;
     updateCoinControlState(coin_control);
-    coin_control.m_feerate = boost::none; // Explicitly use only fee estimation rate for smart fee labels
+    coin_control.m_feerate.reset(); // Explicitly use only fee estimation rate for smart fee labels
     FeeCalculation feeCalc;
-    bool conservative_estimate = CalculateEstimateType(FeeEstimateMode::UNSET, coin_control.signalRbf);
-    CFeeRate feeRate = ::feeEstimator.estimateSmartFee(*coin_control.m_confirm_target, &feeCalc, ::mempool, conservative_estimate);
+    CFeeRate feeRate = CFeeRate(CWallet::GetMinimumFee(1000, coin_control, ::mempool, ::feeEstimator, &feeCalc));
 
-    if (feeRate <= CFeeRate(0)) // not enough data => minfee
-    {
-        ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(),
-                                                                std::max(CWallet::fallbackFee.GetFeePerK(), CWallet::GetRequiredFee(1000))) + "/kB");
+    ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kB");
+
+    if (feeCalc.reason == FeeReason::FALLBACK) {
         ui->labelSmartFee2->show(); // (Smart fee not initialized yet. This usually takes a few blocks...)
         ui->labelFeeEstimation->setText("");
         ui->fallbackFeeWarningLabel->setVisible(true);
@@ -685,8 +683,6 @@ void SendCoinsDialog::updateSmartFeeLabel()
     }
     else
     {
-        ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(),
-                                                                std::max(feeRate.GetFeePerK(), CWallet::GetRequiredFee(1000))) + "/kB");
         ui->labelSmartFee2->hide();
         ui->labelFeeEstimation->setText(tr("Estimated to begin confirmation within %n block(s).", "", feeCalc.returnedTarget));
         ui->fallbackFeeWarningLabel->setVisible(false);
diff --git a/src/wallet/coincontrol.h b/src/wallet/coincontrol.h
index 40c8b764b..fc0e7c519 100644
--- a/src/wallet/coincontrol.h
+++ b/src/wallet/coincontrol.h
@@ -43,9 +43,9 @@ public:
         fAllowOtherInputs = false;
         fAllowWatchOnly = false;
         setSelected.clear();
-        m_feerate = boost::none;
+        m_feerate.reset();
         fOverrideFeeRate = false;
-        m_confirm_target = boost::none;
+        m_confirm_target.reset();
         signalRbf = fWalletRbf;
         m_fee_mode = FeeEstimateMode::UNSET;
     }
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index f010ff0ca..f7f296bd5 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2945,8 +2945,11 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_c
     else { // 2. or 4.
         // We will use smart fee estimation
         unsigned int target = coin_control.m_confirm_target ? *coin_control.m_confirm_target : ::nTxConfirmTarget;
+        // By default estimates are economical iff we are signaling opt-in-RBF
+        bool conservative_estimate = !coin_control.signalRbf;
         // Allow to override the default fee estimate mode over the CoinControl instance
-        bool conservative_estimate = CalculateEstimateType(coin_control.m_fee_mode, coin_control.signalRbf);
+        if (coin_control.m_fee_mode == FeeEstimateMode::CONSERVATIVE) conservative_estimate = true;
+        else if (coin_control.m_fee_mode == FeeEstimateMode::ECONOMICAL) conservative_estimate = false;
 
         fee_needed = estimator.estimateSmartFee(target, feeCalc, pool, conservative_estimate).GetFee(nTxBytes);
         if (fee_needed == 0) {
@@ -4194,15 +4197,3 @@ bool CMerkleTx::AcceptToMemoryPool(const CAmount& nAbsurdFee, CValidationState&
 {
     return ::AcceptToMemoryPool(mempool, state, tx, true, NULL, NULL, false, nAbsurdFee);
 }
-
-bool CalculateEstimateType(FeeEstimateMode mode, bool opt_in_rbf) {
-    switch (mode) {
-    case FeeEstimateMode::UNSET:
-        return !opt_in_rbf; // Allow for lower fees if RBF is an option
-    case FeeEstimateMode::CONSERVATIVE:
-        return true;
-    case FeeEstimateMode::ECONOMICAL:
-        return false;
-    }
-    return true;
-}
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 3c866776f..bb9d146a2 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1213,6 +1213,4 @@ bool CWallet::DummySignTx(CMutableTransaction &txNew, const ContainerType &coins
     return true;
 }
 
-bool CalculateEstimateType(FeeEstimateMode mode, bool opt_in_rbf);
-
 #endif // BITCOIN_WALLET_WALLET_H