Using the information from Wiki and the postal website yes.

Most places aren't as generous with airmail prices, in the UK price bands start at 20g so an all inclusive up to 50g is great {up} I believe Australia also offer a flat rate up to 50g.

If you wanted to be sure i bet ANPost have a contact form somewhere where you can check.

[quote="kimmylee"]1 IRC can be exchanged for the value of an airmail letter weighing up to 20g.

http://en.wikipedia.org/wiki/International_reply_coupon

I just had a look on their website and it seems they will send airmail letters up to 50g worldwide for 0.90 EURO so you should be fine with 1 {up}

http://www.anpost.ie/AnPost/PostalRates/Standard+Post.htm

I don't know if you checked already but they do have size limits:
http://www.anpost.ie/AnPost/What+Are+You+Sending+Details.htm#letter

So if your SASE falls into large letter you would need 2 IRC's.[/quote]

My letter weight 6 g and it is small, normal envelope. So, you think one IRC is enough? :D

1 IRC can be exchanged for the value of an airmail letter weighing up to 20g.

http://en.wikipedia.org/wiki/International_reply_coupon

I just had a look on their website and it seems they will send airmail letters up to 50g worldwide for 0.90 EURO so you should be fine with 1 {up}

http://www.anpost.ie/AnPost/PostalRates/Standard+Post.htm

I don't know if you checked already but they do have size limits:
http://www.anpost.ie/AnPost/What+Are+You+Sending+Details.htm#letter

So if your SASE falls into large letter you would need 2 IRC's.

Hi! I want to send some letters from Poland to Ireland and I need to know how much coupons I need include. My SASE weights 6 grams and by this calculator - http://postage.anpost.ie/ my SASE is worth something about 0.90 €. And I don't know how much one IRC is worth in Ireland. I'm asking because IRC in Poland are a bit expensive and I don't want to waste this coupons. Thank you for answer.

Have a nice day!

Gitaros