diff --git a/notebook/log.py b/notebook/log.py
index 64b35d811..3621a70ca 100644
--- a/notebook/log.py
+++ b/notebook/log.py
@@ -7,7 +7,8 @@
 
 import json
 from tornado.log import access_log
-from .metrics import prometheus_log_method
+from .prometheus.log_functions import prometheus_log_method
+
 
 def log_request(handler):
     """log a bit more information about each request than tornado's default
diff --git a/notebook/prometheus/__init__.py b/notebook/prometheus/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/notebook/metrics.py b/notebook/prometheus/log_functions.py
similarity index 68%
rename from notebook/metrics.py
rename to notebook/prometheus/log_functions.py
index 24a08d8c8..338b59d0d 100644
--- a/notebook/metrics.py
+++ b/notebook/prometheus/log_functions.py
@@ -1,18 +1,5 @@
-"""
-Prometheus metrics exported by Jupyter Notebook Server
+from notebook.prometheus.metrics import HTTP_REQUEST_DURATION_SECONDS
 
-Read https://prometheus.io/docs/practices/naming/ for naming
-conventions for metrics & labels.
-"""
-
-from prometheus_client import Histogram
-
-# This is a fairly standard name for HTTP duration latency reporting
-HTTP_REQUEST_DURATION_SECONDS = Histogram(
-    'http_request_duration_seconds',
-    'duration in seconds for all HTTP requests',
-    ['method', 'handler', 'status_code'],
-)
 
 def prometheus_log_method(handler):
     """
diff --git a/notebook/prometheus/metrics.py b/notebook/prometheus/metrics.py
new file mode 100644
index 000000000..c4defa772
--- /dev/null
+++ b/notebook/prometheus/metrics.py
@@ -0,0 +1,21 @@
+"""
+Prometheus metrics exported by Jupyter Notebook Server
+
+Read https://prometheus.io/docs/practices/naming/ for naming
+conventions for metrics & labels.
+"""
+
+
+from prometheus_client import Histogram, Gauge
+
+
+HTTP_REQUEST_DURATION_SECONDS = Histogram(
+    'http_request_duration_seconds',
+    'duration in seconds for all HTTP requests',
+    ['method', 'handler', 'status_code'],
+)
+
+TERMINAL_CURRENTLY_RUNNING_TOTAL = Gauge(
+    'terminal_currently_running_total',
+    'counter for how many terminals are running',
+)
diff --git a/notebook/terminal/api_handlers.py b/notebook/terminal/api_handlers.py
index 059cc9165..b6f4df155 100644
--- a/notebook/terminal/api_handlers.py
+++ b/notebook/terminal/api_handlers.py
@@ -1,7 +1,8 @@
 import json
 from tornado import web, gen
 from ..base.handlers import APIHandler
-from ..utils import url_path_join
+from notebook.prometheus.metrics import TERMINAL_CURRENTLY_RUNNING_TOTAL
+
 
 class TerminalRootHandler(APIHandler):
     @web.authenticated
@@ -9,12 +10,16 @@ class TerminalRootHandler(APIHandler):
         tm = self.terminal_manager
         terms = [{'name': name} for name in tm.terminals]
         self.finish(json.dumps(terms))
+        TERMINAL_CURRENTLY_RUNNING_TOTAL.set(
+            len(terms)
+        )
 
     @web.authenticated
     def post(self):
         """POST /terminals creates a new terminal and redirects to it"""
         name, _ = self.terminal_manager.new_named_terminal()
         self.finish(json.dumps({'name': name}))
+        TERMINAL_CURRENTLY_RUNNING_TOTAL.inc()
 
 
 class TerminalHandler(APIHandler):
@@ -36,5 +41,6 @@ class TerminalHandler(APIHandler):
             yield tm.terminate(name, force=True)
             self.set_status(204)
             self.finish()
+            TERMINAL_CURRENTLY_RUNNING_TOTAL.dec(1)
         else:
             raise web.HTTPError(404, "Terminal not found: %r" % name)