**@@ 1,1 1,45 @@**
-Calculate your calories burned hiking
+`calculate` is a command line tool for estimating calories burned while
+hiking.
+
+# Basic usage:
+
+```
+calories weight(kg) distance(km) time(min)
+```
+for example: `calories 76 5 60`
+If you want to specify a nonzero elevation gain, use the `-e` flag:
+
+```
+calories -e elevation(m) weight distance time
+```
+It always assumes that it's a round trip and the net elevation gain is zero.
+
+It also supports US Customary units:
+
+```
+calories --us-units -e elevation(ft) weight(lbs) distance(mi) time(min)
+```
+
+# Equations:
+
+The equation used by default is the Load Carriage Decision Aid (LCDA)
+as calibrated by Looney, Santee, *et al.* in *Estimating Energy
+Expenditure during Level, Uphill, and Downhill Walking*.
+
+There are two other equations available:
+- The Pandolf equation (`-q pandolf`) with the
+correction factor for negative slope values derived by Santee *et al.*
+in *Load Carriage Model Development and Testing with Field Data*.
+- The Cost of Walking equation (`-q minetti`) derived by Minetti *et
+ al.* in *Energy cost of walking and running at extreme uphill and
+ downhill slopes*.
+
+# Note
+
+I wrote this as a tool for my own use and as an exercise to practice
+writing Go, which I'm currently learning. I'm a beginner and not a
+programmer, so it's likely poorly written. Any feedback is welcome!
+
+Also, this is not a medical tool, and I know nothing about sports
+medicine and medicine in general. Take the results with a fistful of
+salt and let me know if you have any improvement!