diff --git a/graphs/data/fitShieldRegen/getter.py b/graphs/data/fitShieldRegen/getter.py
index 484b03c29..71f19f7ef 100644
--- a/graphs/data/fitShieldRegen/getter.py
+++ b/graphs/data/fitShieldRegen/getter.py
@@ -35,6 +35,7 @@ class Time2ShieldAmountGetter(SmoothPointGetter):
         shieldAmount = calculateShieldAmount(
             maxShieldAmount=commonData['maxShieldAmount'],
             shieldRegenTime=commonData['shieldRegenTime'],
+            shieldAmountT0=miscParams['shieldAmountT0'] or 0,
             time=time)
         return shieldAmount
 
@@ -51,6 +52,7 @@ class Time2ShieldRegenGetter(SmoothPointGetter):
         shieldAmount = calculateShieldAmount(
             maxShieldAmount=commonData['maxShieldAmount'],
             shieldRegenTime=commonData['shieldRegenTime'],
+            shieldAmountT0=miscParams['shieldAmountT0'] or 0,
             time=time)
         shieldRegen = calculateShieldRegen(
             maxShieldAmount=commonData['maxShieldAmount'],
@@ -83,10 +85,10 @@ class ShieldAmount2ShieldRegenGetter(SmoothPointGetter):
         return shieldRegen
 
 
-def calculateShieldAmount(maxShieldAmount, shieldRegenTime, time):
+def calculateShieldAmount(maxShieldAmount, shieldRegenTime, shieldAmountT0, time):
     # The same formula as for cap
     # https://wiki.eveuniversity.org/Capacitor#Capacitor_recharge_rate
-    return maxShieldAmount * (1 + math.exp(5 * -time / shieldRegenTime) * -1) ** 2
+    return maxShieldAmount * (1 + math.exp(5 * -time / shieldRegenTime) * (math.sqrt(shieldAmountT0 / maxShieldAmount) - 1)) ** 2
 
 
 def calculateShieldRegen(maxShieldAmount, shieldRegenTime, currentShieldAmount):
diff --git a/graphs/data/fitShieldRegen/graph.py b/graphs/data/fitShieldRegen/graph.py
index 4aab3e7b4..c1d849f16 100644
--- a/graphs/data/fitShieldRegen/graph.py
+++ b/graphs/data/fitShieldRegen/graph.py
@@ -36,7 +36,9 @@ class FitShieldRegenGraph(FitGraph):
         Input(handle='shieldAmount', unit='%', label='Shield amount', iconID=1384, defaultValue=25, defaultRange=(0, 100), conditions=[
             (('shieldAmount', 'EHP'), None),
             (('shieldAmount', 'HP'), None),
-            (('shieldAmount', '%'), None)])]
+            (('shieldAmount', '%'), None)]),
+        Input(handle='shieldAmountT0', unit='%', label='Starting shield amount', iconID=1384, defaultValue=0, defaultRange=(0, 100), conditions=[
+            (('time', 's'), None)])]
     srcExtraCols = ('ShieldAmount', 'ShieldTime')
     usesHpEffectivity = True
 
@@ -56,9 +58,12 @@ class FitShieldRegenGraph(FitGraph):
     # Calculation stuff
     _normalizers = {
         ('shieldAmount', '%'): lambda v, src, tgt: v / 100 * src.item.ship.getModifiedItemAttr('shieldCapacity'),
+        ('shieldAmountT0', '%'): lambda v, src, tgt: None if v is None else v / 100 * src.item.ship.getModifiedItemAttr('shieldCapacity'),
         # Needed only for "x mark" support, to convert EHP x into normalized value
         ('shieldAmount', 'EHP'): lambda v, src, tgt: v / src.item.damagePattern.effectivify(src.item, 1, 'shield')}
-    _limiters = {'shieldAmount': lambda src, tgt: (0, src.item.ship.getModifiedItemAttr('shieldCapacity'))}
+    _limiters = {
+        'shieldAmount': lambda src, tgt: (0, src.item.ship.getModifiedItemAttr('shieldCapacity')),
+        'shieldAmountT0': lambda src, tgt: (0, src.item.ship.getModifiedItemAttr('shieldCapacity'))}
     _getters = {
         ('time', 'shieldAmount'): Time2ShieldAmountGetter,
         ('time', 'shieldRegen'): Time2ShieldRegenGetter,