diff --git a/src/claude_statusbar/core.py b/src/claude_statusbar/core.py
index 5dd75b8..e9fe66d 100755
--- a/src/claude_statusbar/core.py
+++ b/src/claude_statusbar/core.py
@@ -727,6 +727,22 @@ def _get(key):
     return None
 
 
+def _exact_used_tokens(stdin_data: Dict[str, Any]) -> Optional[int]:
+    """Context tokens as Claude Code reported them, or None when unavailable.
+
+    None means "no usable signal" — an older Claude Code that omits the
+    totals, a relay payload that zeroes them, or a malformed value. Callers
+    fall back to deriving the count from the percentage.
+    """
+    total = 0
+    for key in ('total_input_tokens', 'total_output_tokens'):
+        try:
+            total += int(stdin_data.get(key, 0) or 0)
+        except (TypeError, ValueError):
+            return None
+    return total or None
+
+
 def _context_window_usage(stdin_data: Dict[str, Any],
                           env=None) -> Tuple[Optional[float], int, int]:
     """Return (ctx_pct, ctx_size, ctx_used) for renderer/model suffix.
@@ -752,13 +768,15 @@ def _context_window_usage(stdin_data: Dict[str, Any],
     except (TypeError, ValueError):
         ctx_pct = None
 
-    if ctx_pct is not None:
-        ctx_used = int(ctx_size_f * ctx_pct / 100)
-    else:
-        ctx_used = (
-            stdin_data.get('total_input_tokens', 0)
-            + stdin_data.get('total_output_tokens', 0)
-        )
+    # Exact totals beat the integer percentage. Claude Code reports
+    # used_percentage as a whole number, so deriving tokens from it quantises
+    # the readout to 1% of the window — 2k on a 200k model (invisible), but
+    # 10k on a 1M-context one, where the bar steps 60.0k → 70.0k and can sit
+    # ~10k off the truth. `ctx_pct` itself stays as reported so the percentage
+    # and its severity colour keep matching what Claude Code shows.
+    ctx_used = _exact_used_tokens(stdin_data)
+    if ctx_used is None:
+        ctx_used = int(ctx_size_f * ctx_pct / 100) if ctx_pct is not None else 0
 
     # Env override (#29): used tokens stay what stdin reported; the window and
     # the percentage are re-derived against the real (env-forced) size.
diff --git a/tests/test_core_ctx_pct.py b/tests/test_core_ctx_pct.py
index 8da4a02..592da77 100644
--- a/tests/test_core_ctx_pct.py
+++ b/tests/test_core_ctx_pct.py
@@ -34,6 +34,37 @@ def test_normal_context_returns_float():
     assert isinstance(out, float)
 
 
+def test_used_tokens_come_from_exact_totals_not_rounded_pct():
+    """used_percentage is a whole number; on a 1M window that quantises the
+    token readout to 10k steps. The exact totals must win."""
+    ctx_pct, _, ctx_used = core._context_window_usage({
+        "context_window_size": 1_000_000,
+        "context_used_pct": 6,
+        "total_input_tokens": 63_824,
+        "total_output_tokens": 0,
+    })
+    assert ctx_used == 63_824  # not 60_000
+    assert ctx_pct == 6.0      # percentage stays as Claude Code reported it
+
+
+def test_used_tokens_fall_back_to_pct_when_totals_absent():
+    """Older Claude Code / relay payloads omit the totals entirely."""
+    _, _, ctx_used = core._context_window_usage({
+        "context_window_size": 200_000,
+        "context_used_pct": 25,
+    })
+    assert ctx_used == 50_000
+
+
+def test_malformed_totals_fall_back_to_pct():
+    _, _, ctx_used = core._context_window_usage({
+        "context_window_size": 200_000,
+        "context_used_pct": 25,
+        "total_input_tokens": "lots",
+    })
+    assert ctx_used == 50_000
+
+
 def test_null_context_pct_is_unknown_not_error():
     ctx_pct, ctx_size, ctx_used = core._context_window_usage({
         "context_window_size": 1_000_000,