You actually have that the wrong way round.
If you have a 2:1 risk-reward it means you’re risking 2 units to win 1.
If you’re risking 1 unit to try to win 2, as you describe, that’s (naturally enough) called a 1:2 risk-reward, because it’s 1-risk and 2-reward. 
By the way, this widespread point of confusion’s been discussed here many times! These threads will help anyone interested. 
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