The free online GST and GST Free Portion Calculator! Provided here for your use. Please make sure you report any issues with the calculator in the comments below. Enjoy your calculations!
I wrote this simple little script in JavaScript to help me calculate Australian GST (10%) today. Being such a useful little script, I thought I would post it.
Please feel free to use this script as your require, if you wish to have this script on your own website please post an acknowledgement and link back to this page.
How to Calculate GST the hard way (using you know, numbers and shit)
If you have something without GST, and you need it with GST, you add 10%. Which is easilest done on a calculator by multiplying your amount by 1.1 (which is really saying mister Calculator, give me 110% of this amount).
$100 * 1.1 = $110
To go the other way, let's say we have $110, which includes 10% GST already. Working out how much is the GST part is quickly done on a calculator by dividing by 11. Not 10 you say? No, 11. Because easiestly explained, before GST you had 10 parts of a number, the "extra" 10% is another "part". So we need to work out what that part is.
$110 / 11 = $10
Huzzah! We have the GST component of an amount! Now, we need to take that GST part from our original amount of $110 to get what the amount is without GST.
$110 - $10 = $100
Perfect :-)
But seriously, why do all this manual work when this GST calculator does it for you?
Last Updated 04/03/2014: Fixed floating point arithmetic (Loss of 1c on some calculations). Thanks to Michael for pointing it out.
Have just found this site and first thing done was save to fav
THANK YOU!!!!!!!!!!!!!!!!!!!
Love it! Thanks!! Have already added this website to my favourites 🙂
fabulous aid
Great little tool. Thanks heaps.
THANKS MATE YOU MAKE LIFE A LITTLE EASIER
awww! you just save me! i don’t have any idea re Australian Taxation… my boss just give me a go with this load! thanks heaps!
ps it would save me doing the calculation and then maually adding it to the pdf printout. A
hi Im this little formula is perfect … i have written an tax invoice in html and i cant get the subtotal total bit to work … im new at this so i am only guessing as i go along … is there a way to add your script to my tax invoice??
thanks
Ange
hrmm, do you have access to adjust the code in the backend yourself? The math or formula for just the GST stuff is just $Amount * 1.1 to add GST. $Amount / 11 to remove it.
Hi thanks for replying… I can access the backend … the tax invoice is written in html and the balances are in java which someone else wrote for me but the set up is wrong and so it doesnt work. if i can cut and paste the formula so it shows gst subtotal and then total .. maybe a line for deducting payment/s before the total i can try to add it and see if i can make it work. A
If you can copy/paste the totalling function in an email to me, I’ll take a look one day soon. Use the contact form.
Life saver! Every time I got my bill from Telstra I’d come up against my own mathematical inadequacies trying to figure out the GST free component of the invoice.
You just saved me a whole pile of time, thank you!
maybe an i phone app 🙂
Maybe!
Sounds good 😉
This is brilliant thank you, so easy to use
Champion! Will save me time when using crappy PO tools.
it’s so easy to use, thank you. I love it
thankyou so much!! really helped me out
Very helpful. I just cant thank you enough for coming up with this brilliant calculator.
Thanks Dazza, this site has been my saving grace!
Great for the lamen like me !!!
THANK YOU – BLOODY LEGEND!!! XX
Thanks so much!
You’re a life saver!
Great! Thanks. One of my favourites!
GREAT! Really helped me out~
Getting better by the version 🙂 Thanks Darren – appreciate your work!
Love it! Thanks
AWESOME!!!! Will save this to my favorites:)