diff --git a/bia/formulas.py b/bia/formulas.py
new file mode 100644
index 0000000..503d834
--- /dev/null
+++ b/bia/formulas.py
@@ -0,0 +1,23 @@
+import math
+
+
+def one_rm_epley(weight, reps):
+    return weight * (1 + (reps / 30.0))
+
+def one_rm_brzycki(weight, reps):
+    return weight * (36 / (37.0 - reps))
+
+def one_rm_lander(weight, reps):
+    return (100 * weight) / (101.3 - 2.67123 * reps)
+
+def one_rm_lombardi(weight, reps):
+    return weight * (reps ** 0.1)
+
+def one_rm_mayhew(weight, reps):
+    return (100 * weight) / (52.2 + 41.9 * math.e ** (-0.055*reps))
+
+def one_rm_oconner(weight, reps):
+    return weight * (1 + 0.025 * reps)
+
+def one_rm_wathen(weight, reps):
+    return (100 * weight) / (48.8 + 53.8 * math.e ** (-0.075*reps))