diff --git a/views.py b/views.py
index 8e90c09..9d80b97 100644
--- a/views.py
+++ b/views.py
@@ -251,6 +251,7 @@ class UpperLimitView(APIView):
         # BAYESIAN IMPLEMENTATION VIA POISSON_CONF_INTERVAL
         # **************************************************************
 
+        # double sided interval
         low, high = poisson_conf_interval(
             n=N,
             background=B,
@@ -262,26 +263,42 @@ class UpperLimitView(APIView):
         bayesian_count_ul = high[0]
         bayesian_count_ll = low[0]
 
+        bayesian_count_UL = (
+            sp.gammaincinv(
+                N + 1, confidence_level * sp.gammaincc(N + 1, B) + sp.gammainc(N + 1, B)
+            )
+            - B
+        )
+
         bayesian_rate_ul = bayesian_count_ul / t / EEF  # count rate limits
         bayesian_rate_ll = bayesian_count_ll / t / EEF
+        bayesian_rate_UL = bayesian_count_UL / t / EEF
 
         bayesian_flux_ul = bayesian_rate_ul * ECF  # flux limits
         bayesian_flux_ll = bayesian_rate_ll * ECF
+        bayesian_flux_UL = bayesian_rate_UL * ECF
 
         # CLASSICAL IMPLEMENTATION VIA GAMMAINCCINV
         # ****************************************************************
 
-        classic_count_ul = sp.gammainccinv(N + 1, 1 - confidence_level) - B
-        classic_count_ll = sp.gammainccinv(N, confidence_level) - B
+        # confidence level for the double sided interval
+        cl2 = (1 + confidence_level) / 2
+        # double sided interval
+        classic_count_ul = sp.gammainccinv(N + 1, 1 - cl2) - B
+        classic_count_ll = sp.gammainccinv(N, cl2) - B
+        # one sided interval
+        classic_count_UL = sp.gammainccinv(N + 1, 1 - confidence_level) - B
 
         if not np.isfinite(classic_count_ll) or classic_count_ll < 0:
             classic_count_ll = 0.0
 
         classic_rate_ul = classic_count_ul / t / EEF  # count rate limits
         classic_rate_ll = classic_count_ll / t / EEF
+        classic_rate_UL = classic_count_UL / t / EEF
 
         classic_flux_ul = classic_rate_ul * ECF  # flux limits
         classic_flux_ll = classic_rate_ll * ECF
+        classic_flux_UL = classic_rate_UL * ECF
 
         # FLUX ESTIMATION
         # ****************************************************************
@@ -392,17 +409,23 @@ class UpperLimitView(APIView):
             # frequentist limits
             "ClassicUpperLimit": classic_count_ul,
             "ClassicLowerLimit": classic_count_ll,
+            "ClassicOneSideUL": classic_count_UL,
             "ClassicCountRateUpperLimit": classic_rate_ul,
             "ClassicCountRateLowerLimit": classic_rate_ll,
+            "ClassicCountRateOneSideUL": classic_rate_UL,
             "ClassicFluxUpperLimit": classic_flux_ul,
             "ClassicFluxLowerLimit": classic_flux_ll,
+            "ClassicFluxOneSideUL": classic_flux_UL,
             # bayesian limits
             "BayesianUpperLimit": bayesian_count_ul,
             "BayesianLowerLimit": bayesian_count_ll,
+            "BayesianOneSideUL": bayesian_count_UL,
             "BayesianCountRateUpperLimit": bayesian_rate_ul,
             "BayesianCountRateLowerLimit": bayesian_rate_ll,
+            "BayesianCountRateOneSideUL": bayesian_rate_UL,
             "BayesianFluxUpperLimit": bayesian_flux_ul,
             "BayesianFluxLowerLimit": bayesian_flux_ll,
+            "BayesianFluxOneSideUL": bayesian_flux_UL,
             # flux 'center value' estimate
             "FluxEstimate": Flux,
             # raw data