diff --git a/fava_client.py b/fava_client.py
index 76aa022..e300867 100644
--- a/fava_client.py
+++ b/fava_client.py
@@ -111,13 +111,16 @@ class FavaClient:
         """
         Get balance for a specific account (excluding pending transactions).
 
+        Uses sum(weight) for efficient SATS aggregation from price notation.
+
         Args:
             account_name: Full account name (e.g., "Assets:Receivable:User-abc123")
 
         Returns:
             Dict with:
-                - sats: int (balance in satoshis)
-                - positions: dict (currency → amount with cost basis)
+                - sats: int (balance in satoshis from weight column)
+                - fiat: Decimal (balance in fiat currency from number column)
+                - fiat_currency: str (currency code, defaults to EUR)
 
         Note:
             Excludes pending transactions (flag='!') from balance calculation.
@@ -125,12 +128,13 @@ class FavaClient:
 
         Example:
             balance = await fava_client.get_account_balance("Assets:Receivable:User-abc")
-            # Returns: {
-            #     "sats": 200000,
-            #     "positions": {"SATS": {"{100.00 EUR}": 200000}}
-            # }
+            # Returns: {"sats": 200000, "fiat": Decimal("150.00"), "fiat_currency": "EUR"}
         """
-        query = f"SELECT sum(position) WHERE account = '{account_name}' AND flag != '!'"
+        from decimal import Decimal
+
+        # Use sum(weight) for SATS and sum(number) for fiat
+        # Note: BQL doesn't support != operator, so use flag = '*' to exclude pending
+        query = f"SELECT sum(number), sum(weight) WHERE account = '{account_name}' AND flag = '*'"
 
         try:
             async with httpx.AsyncClient(timeout=self.timeout) as client:
@@ -141,26 +145,26 @@ class FavaClient:
                 response.raise_for_status()
                 data = response.json()
 
-            if not data['data']['rows']:
-                return {"sats": 0, "positions": {}}
+            if not data['data']['rows'] or not data['data']['rows'][0]:
+                return {"sats": 0, "fiat": Decimal(0), "fiat_currency": "EUR"}
 
-            # Fava returns: [[account, {"SATS": {cost: amount}}]]
-            positions = data['data']['rows'][0][1] if data['data']['rows'] else {}
+            row = data['data']['rows'][0]
+            fiat_sum = row[0] if len(row) > 0 else 0
+            weight_sum = row[1] if len(row) > 1 else {}
 
-            # Sum up all SATS positions
+            # Parse fiat amount
+            fiat_amount = Decimal(str(fiat_sum)) if fiat_sum else Decimal(0)
+
+            # Parse SATS from weight column
             total_sats = 0
-            if isinstance(positions, dict) and "SATS" in positions:
-                sats_positions = positions["SATS"]
-                if isinstance(sats_positions, dict):
-                    # Sum all amounts (with different cost bases)
-                    total_sats = sum(int(amount) for amount in sats_positions.values())
-                elif isinstance(sats_positions, (int, float)):
-                    # Simple number (no cost basis)
-                    total_sats = int(sats_positions)
+            if isinstance(weight_sum, dict) and "SATS" in weight_sum:
+                sats_value = weight_sum["SATS"]
+                total_sats = int(Decimal(str(sats_value)))
 
             return {
                 "sats": total_sats,
-                "positions": positions
+                "fiat": fiat_amount,
+                "fiat_currency": "EUR"  # Default, could be extended to detect currency
             }
 
         except httpx.HTTPStatusError as e:
diff --git a/views_api.py b/views_api.py
index 86b96e6..7589d54 100644
--- a/views_api.py
+++ b/views_api.py
@@ -309,7 +309,8 @@ async def api_get_account_balance(account_id: str) -> dict:
     return {
         "account_id": account_id,
         "balance": balance_data["sats"],  # Balance in satoshis
-        "positions": balance_data["positions"]  # Full Beancount positions with cost basis
+        "fiat": float(balance_data.get("fiat", 0)),  # Fiat amount
+        "fiat_currency": balance_data.get("fiat_currency", "EUR")
     }