MrMalty calc says 79ml

So according to mrmatly pitching rate calculator, I need to pitch 79ml of slurry. Right now, my slurry (washed and started) is in a 1L flask in my fridge and I have, maybe, 1/4" of yeast at the bottom of my starter wort - it doesn't even reach the top of the curve on the bottom of the flask.

I have no clue how many ml of yeast that works out to.

My question:

Do you estimate your yeast amount? Do you mark up your containers? Do you decant the wort and then measure the yeast? ???

Without knowing the volume, I feel like I'm just blindly guessing and should not even worry about pitching rates. Before now, I've just pitched a smack pack per batch (underpitching, I understand) and everything has been fine.

I'm sure that with experience, I'll know what amount is right without measuring, but I'm worried that if I fuss about and try to measure with accuracy, I will contaminate my yeast or something.

Are you pitching from slurry? Or from a starter you made from a smackpack?

The slurry calculator is meant to be used when you have washed yeast from a previous batch. If you give us the details (size and expected OG) of your planned brew we can double check your math.

Slurry. I washed the yeast and made a 1L starter and got about 50ml of good yeast from it. I ended up combining the other half of my washed yeast (still have half a growler of hoppy sludge) and got close to 100ml of good, clear 1056 yeast. By the time I pitched it, the yeast was still chugging on the last bits of wort in the vial and seemed quite happy. I attached a blow-off tube just in case, but I am hoping for a good hard fermentation. It's been about a hour since pitching and the bucket is pressurizing but not bubbling, yet.

Going back to my original question, I had no idea what 97ml of yeast looked like until I decanted and poured the yeast into a (sanitized) measuring cup. Now I have a better idea of what 'halfway up the curve on the bottom of the 1L flask' means for next time and can hopefully avoid that extra transfer.