diff --git a/tests/metpy_simpletest.py b/tests/metpy_simpletest.py
new file mode 100644
index 0000000..0c42e35
--- /dev/null
+++ b/tests/metpy_simpletest.py
@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
+# SPDX-FileCopyrightText: Copyright (c) 2021 Arofarn
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Same as umetpy_simpletest but for original MetPy module, to compare and validate results"""
+
+import metpy.constants as mpconsts
+
+# pylint: disable=eval-used
+print("List of all constants:\n")
+for cst in dir(mpconsts):
+    if cst[0] != "_" and cst not in ["exporter", "units"]:
+        print("{:30s} = {:.12f}".format(cst, eval("{}.{}".format("mpconsts", cst))))
diff --git a/umetpy/constants.py b/umetpy/constants.py
index 10774e5..544369c 100644
--- a/umetpy/constants.py
+++ b/umetpy/constants.py
@@ -71,10 +71,9 @@ molecular_weight_ratio   :math:`\epsilon`  epsilon     :math:`\text{None}`
 .. [7] [WMO1966]_
 .. [8] [Picard2008]_
 """  # noqa: E501
-
 # pylint: enable=line-too-long
-
 # pylint: disable=invalid-name
+
 from .package_tools import Exporter
 
 exporter = Exporter(globals())
@@ -82,53 +81,55 @@ exporter = Exporter(globals())
 # Export all the variables defined in this block
 with exporter:
     # Earth
-    earth_gravity = g = 9.80665  # 'm / s^2'
-    Re = earth_avg_radius = 6371008.7714  # 'm'
-    G = gravitational_constant = 6.67430e-11  # 'm^3 / kg / s^2'
-    GM = geocentric_gravitational_constant = 3986005e8  # 'm^3 / s^2'
-    omega = earth_avg_angular_vel = 7292115e-11  # 'rad / s'
-    d = earth_sfc_avg_dist_sun = 149597870700.0  # 'm'
-    S = earth_solar_irradiance = 1360.8  # 'W / m^2'
-    delta = earth_max_declination = 23.45  # 'degrees'
-    earth_orbit_eccentricity = 0.0167  # 'dimensionless'
-    earth_mass = me = geocentric_gravitational_constant / gravitational_constant
+    earth_gravity = g = 9.80665  # 'm / s^2' x
+    Re = earth_avg_radius = 6371008.7714  # 'm' x
+    G = gravitational_constant = 6.67430e-11  # 'm^3 / kg / s^2' x
+    GM = geocentric_gravitational_constant = 3986005e8  # 'm^3 / s^2' x
+    omega = earth_avg_angular_vel = 7292115e-11  # 'rad / s' x
+    d = earth_sfc_avg_dist_sun = 149597870700.0  # 'm' x
+    S = earth_solar_irradiance = 1360.8  # 'W / m^2' x
+    delta = earth_max_declination = 23.45  # 'degrees' x
+    earth_orbit_eccentricity = 0.0167  # 'dimensionless' x
+    earth_mass = me = 5972169366075843731783680  # 'kg' x
 
     # molar gas constant
-    R = 8.314462618  # 'J / mol / K'
+    R = 8.314462618  # 'J / mol / K' x
 
     # Water
-    Mw = water_molecular_weight = 18.015268  # 'g / mol'
-    Rv = water_gas_constant = R / Mw
-    rho_l = density_water = 999.97495  # 'kg / m^3'
-    wv_specific_heat_ratio = 1.330  # 'dimensionless'
-    Cp_v = wv_specific_heat_press = (
-        wv_specific_heat_ratio * Rv / (wv_specific_heat_ratio - 1)
-    )
-    Cv_v = wv_specific_heat_vol = Cp_v / wv_specific_heat_ratio
-    Cp_l = water_specific_heat = 4.2194  # 'kJ / kg / K'
-    Lv = water_heat_vaporization = 2.50084e6  # 'J / kg'
-    Lf = water_heat_fusion = 3.337e5  # 'J / kg'
-    Cp_i = ice_specific_heat = 2090  # 'J / kg / K'
-    rho_i = density_ice = 917  # 'kg / m^3'
+    Mw = water_molecular_weight = 18.015268  # 'g / mol' x
+    Rv = water_gas_constant = 0.461523115726  # 'J / g / K' x
+    rho_l = density_water = 999.97495  # 'kg / m^3' x
+    wv_specific_heat_ratio = 1.330  # 'dimensionless' x
+    # Cp_v = (wv_specific_heat_ratio * Rv / (wv_specific_heat_ratio - 1))
+    Cp_v = wv_specific_heat_press = 1.860078011866  # 'J / g / K' x
+    # Cv_v = Cp_v / wv_specific_heat_ratio
+    Cv_v = wv_specific_heat_vol = 1.398554896140  # 'J / g / K' x
+    Cp_l = water_specific_heat = 4.2194  # 'kJ / kg / K' x
+    Lv = water_heat_vaporization = 2500840  # 'J / kg' x
+    Lf = water_heat_fusion = 333700.0  # 'J / kg' x
+    Cp_i = ice_specific_heat = 2090  # 'J / kg / K' x
+    rho_i = density_ice = 917  # 'kg / m^3' x
 
     # Dry air
-    Md = dry_air_molecular_weight = 28.96546e-3  # 'kg / mol'
-    Rd = dry_air_gas_constant = R / Md
+    Md = dry_air_molecular_weight = 0.02896546  # 'kg / mol' x
+    # Rd = dry_air_gas_constant = R / Md
+    Rd = dry_air_gas_constant = 287.047490977185  # 'J / K / kg` x
     dry_air_spec_heat_ratio = 1.4  # 'dimensionless'
-    Cp_d = dry_air_spec_heat_press = (
-        dry_air_spec_heat_ratio * Rd / (dry_air_spec_heat_ratio - 1)
-    )
-    Cv_d = dry_air_spec_heat_vol = Cp_d / dry_air_spec_heat_ratio
-    # TODO : check unit conversion
-    rho_d = dry_air_density_stp = 1000.0 / (Rd * 273.15)  # 'kg / m^3'
+    # Cp_d = (dry_air_spec_heat_ratio * Rd / (dry_air_spec_heat_ratio - 1))
+    Cp_d = dry_air_spec_heat_press = 1004.666218420146  # 'J / K / kg` x
+    # Cv_d = dry_air_spec_heat_vol = Cp_d / dry_air_spec_heat_ratio
+    Cv_d = dry_air_spec_heat_vol = 717.618727442962  # 'J / K / kg` x
+    # rho_d = dry_air_density_stp = 1000.0 mbar / (Rd * 273.15 K)
+    rho_d = dry_air_density_stp = 1.275395968940  # 'kg / m^3' x
 
     # General meteorology constants
-    P0 = pot_temp_ref_press = 1000.0  # 'mbar'
-    # TODO : check unit conversion
-    kappa = poisson_exponent = Rd / Cp_d  # 'dimensionless'
-    gamma_d = dry_adiabatic_lapse_rate = g / Cp_d
-    # TODO : check unit conversion
-    epsilon = molecular_weight_ratio = Mw / Md  # 'dimensionless'
+    P0 = pot_temp_ref_press = 1000.0  # 'mbar' x
+    # kappa = poisson_exponent = Rd / Cp_d
+    kappa = poisson_exponent = 0.285714285714  # 'dimensionless' x
+    # gamma_d = dry_adiabatic_lapse_rate = g / Cp_d
+    gamma_d = dry_adiabatic_lapse_rate = 0.009761102563  # 'K * kg * m / J / s^2' x
+    # epsilon = molecular_weight_ratio = Mw / Md
+    epsilon = molecular_weight_ratio = 0.621956910058  # 'dimensionless'
 
 del exporter
 del Exporter