diff -r e97f9e87d94b -r 8133cdb19aa1 src/Utils.h
--- a/src/Utils.h	Tue Jul 05 14:31:39 2022 +0200
+++ b/src/Utils.h	Thu Jul 07 08:51:57 2022 +0200
@@ -32,8 +32,60 @@
     double kw_to_ebc(int colormethod, double c);
     double kw_to_newebc(int colormethod, double c);
     double abvol(double og, double fg);
+
+    /**
+     * @brief Calculate standar air pressure at the brewery.
+     *        Assume 20°C and use the global setup height.
+     * @return Pressure in hPa.
+     */
+    double brewery_hPa();
+
+    /**
+     * @brief Return boil temperature in °C at the brewery height.
+     * @return Temperature in °C
+     */
+    double boilPoint();
+
+    /**
+     * @brief Calculate IBU reduction at given temperature.
+     * @param Tc temperature in °C.
+     * @return The reduction factor.
+     */
+    double IBU_reduction(double Tc);
+
+    /**
+     * @brief Calculate IBU's of a hop at 100°C.
+     * @param Use HOP_USEAT_MASH HOP_USEAT_FWH HOP_USEAT_BOIL, all others are ignored.
+     * @param Form HOP_FORMS_PELLET HOP_FORMS_PLUG HOP_FORMS_LEAF HOP_FORMS_LEAF_WET HOP_FORMS_CRYO HOP_FORMS_EXTRACT
+     * @param SG the density
+     * @param Volume in liters
+     * @param Amount in kilograms
+     * @param Time in minutes
+     * @param Alpha in procent
+     * @param Method, 0 = Tinseth, 1 = Rager, 2 = Daniels
+     * @return The calculated IBU's
+     */
+    double boilIBU(int Form, double SG, double Volume, double Amount, double Time, double Alpha, int Method);
+
+    /**
+     * @brief Calculate IBU's of a hop during the whole production process.
+     * @param Use HOP_USEAT_MASH HOP_USEAT_FWH HOP_USEAT_BOIL HOP_USEAT_AROMA HOP_USEAT_WHIRLPOOL HOP_USEAT_DRY_HOP HOP_USEAT_BOTTLING
+     * @param Form HOP_FORMS_PELLET HOP_FORMS_PLUG HOP_FORMS_LEAF HOP_FORMS_LEAF_WET HOP_FORMS_CRYO HOP_FORMS_EXTRACT
+     * @param SG the density
+     * @param Volume in liters
+     * @param Amount in kilograms
+     * @param Boiltime in minutes
+     * @param Alpha in procent
+     * @param Method, 0 = Tinseth, 1 = Rager, 2 = Daniels
+     * @param Whirlpool9 time in whirlpool above 80°C or zero.
+     * @param Whirlpool7 time in whirlpool between 72°C and 77°C.
+     * @param Whirlpool6 time in whirlpool between 60°C amd 66°C.
+     * @param Fulltime, full boiltime, even for aroma hops.
+     * @return The calculated IBU's
+     */
     double toIBU(int Use, int Form, double SG, double Volume, double Amount, double Boiltime, double Alpha,
                  int Method, double Whirlpool9, double Whirlpool7, double Whirlpool6, double Fulltime);
+
     double hopFlavourContribution(double bt, double vol, int use, double amount);
     double hopAromaContribution(double bt, double vol, int use, double amount);
     QString hours_to_string(int hours);