diff --git a/phiml/backend/_dtype.py b/phiml/backend/_dtype.py
index 49d95e7d..b537a001 100644
--- a/phiml/backend/_dtype.py
+++ b/phiml/backend/_dtype.py
@@ -44,7 +44,7 @@ def __init__(self, kind: type, bits: int = None, precision: int = None):
             else:
                 bits = precision * 2
         else:
-            assert isinstance(bits, int)
+            assert isinstance(bits, int), f"bits must be an int but got {type(bits)}"
         self.kind = kind
         """ Python class corresponding to the type of data, ignoring precision. One of (bool, int, float, complex, str) """
         self.bits = bits
diff --git a/phiml/math/__init__.py b/phiml/math/__init__.py
index 2d345b73..1cb90fe5 100644
--- a/phiml/math/__init__.py
+++ b/phiml/math/__init__.py
@@ -92,6 +92,7 @@
     trace_check,
     map_ as map,
     when_available,
+    perf_counter,
 )
 
 from ._optimize import solve_linear, solve_nonlinear, minimize, Solve, SolveInfo, ConvergenceException, NotConverged, Diverged, SolveTape, factor_ilu
diff --git a/phiml/math/_functional.py b/phiml/math/_functional.py
index 1337384c..a883976b 100644
--- a/phiml/math/_functional.py
+++ b/phiml/math/_functional.py
@@ -1,4 +1,5 @@
 import inspect
+import time
 import types
 import warnings
 from functools import wraps, partial
@@ -15,6 +16,7 @@
 from ..backend import Backend, NUMPY
 from ..backend._backend import get_spatial_derivative_order, functional_derivative_evaluation, ML_LOGGER
 from .magic import PhiTreeNode, Shapable
+from ..backend._dtype import DType
 
 X = TypeVar('X')
 Y = TypeVar('Y')
@@ -158,6 +160,7 @@ def __init__(self, f: Callable, auxiliary_args: Set[str], forget_traces: bool):
         self.grad_jit = GradientFunction(f.f, self.f_params, f.wrt, f.get_output, f.is_f_scalar, jit=True) if isinstance(f, GradientFunction) else None
         self._extract_tensors: List[Tuple[Tensor]] = []
         self._post_call: List[Callable] = []
+        self._tracing_in_key: SignatureKey = None
 
     def _jit_compile(self, in_key: SignatureKey):
         ML_LOGGER.debug(f"Φ-ML-jit: '{f_name(self.f)}' called with new key. shapes={[s.volume for s in in_key.shapes]}, args={in_key.tree}")
@@ -165,6 +168,7 @@ def _jit_compile(self, in_key: SignatureKey):
         def jit_f_native(*natives):
             ML_LOGGER.debug(f"Φ-ML-jit: Tracing '{f_name(self.f)}'")
             _TRACING_JIT.append(self)
+            self._tracing_in_key = in_key
             in_tensors = assemble_tensors(natives, in_key.specs)
             kwargs = assemble_tree(in_key.tree, in_tensors)
             f_output = self.f(**kwargs, **in_key.auxiliary_kwargs)  # Tensor or tuple/list of Tensors
@@ -172,6 +176,7 @@ def jit_f_native(*natives):
             result_natives, result_shapes, specs = disassemble_tensors(out_tensors, expand=True)
             self.recorded_mappings[in_key] = SignatureKey(jit_f_native, tree, result_shapes, specs, in_key.backend, in_key.tracing)
             assert _TRACING_JIT.pop(-1) is self
+            self._tracing_in_key = None
             return result_natives
 
         jit_f_native.__name__ = f"native({f_name(self.f) if isinstance(self.f, types.FunctionType) else str(self.f)})"
@@ -1206,3 +1211,28 @@ def identity(x):
         `x`
     """
     return x
+
+
+def perf_counter(wait_for_tensor, *wait_for_tensors: Tensor) -> Tensor:
+    """
+    Get the time (`time.perf_counter()`) at which all `wait_for_tensors` are computed.
+    If all tensors are already available, returns the current `time.perf_counter()`.
+
+    Args:
+        wait_for_tensor: `Tensor` that need to be computed before the time is measured.
+        *wait_for_tensors: Additional tensors that need to be computed before the time is measured.
+
+    Returns:
+        Time at which all `wait_for_tensors` are ready as a scalar `Tensor`.
+    """
+    assert not _TRACING_LINEAR, f"Cannot use perf_counter inside a function decorated with @jit_compile_linear"
+    if not _TRACING_JIT:
+        return wrap(time.perf_counter())
+    else:  # jit
+        backend = _TRACING_JIT[0]._tracing_in_key.backend
+        natives, _, _ = disassemble_tensors([wait_for_tensor, *wait_for_tensors], expand=False)
+        natives = [n for n in natives if backend.is_tensor(n, only_native=True)]
+        assert natives, f"in jit mode, perf_counter must be given at least one traced tensor, as the current time is evaluated after all tensors are computed."
+        def perf_counter(*_wait_for_natives):
+            return np.asarray(time.perf_counter())
+        return wrap(backend.numpy_call(perf_counter, (), DType(float, 64), *natives))
diff --git a/tests/commit/math/test__functional.py b/tests/commit/math/test__functional.py
index 0c9808b5..fd6bdb7a 100644
--- a/tests/commit/math/test__functional.py
+++ b/tests/commit/math/test__functional.py
@@ -291,3 +291,20 @@ def print_x(x):
                 assert CONCRETE
                 assert CONCRETE[0].available
                 assert TRACER
+
+    def test_perf_counter(self):
+        @math.jit_compile
+        def fun(x):
+            t0 = math.perf_counter(x)
+            print("fun called, time=", t0)
+            for i in range(1000):
+                x *= 0.5
+                x += 1
+            dt = math.perf_counter(x) - t0
+            return x, dt
+
+        for backend in BACKENDS:
+            with backend:
+                result, exec_time = fun(tensor(0))
+                print("time taken", 1000_000 * float(exec_time), "result:", result)
+