<prompt> Human: I got frustrated that no one could give me real answers on this so created some equations. NB I am not a math or finance person, so if you have improvements on the equations or find errors, let me know and I will implement them. If you want to tell me what an idiot I am ... just remember Im only posting to help other people out. R your tax ratec your contribution to HSAd plan deductibleDeductible company HSA contribution YTo calculate total cost compare this to annual premium all copays for comparable care alternate health insurance plan total care charges 1500 deductible X1if X -Y Note: if this is the case, HSA is a good deal for youyouve made a profit on your health careX Y CR total expense 2if -Y X 0 -X CXR your share premium total expense3if 0 X out of pocket max D coinsurance rate Xcoinsurance rate Y Contributiontax rate your share annual premium total expenseIf x out of pocket max D coinsurance rate, make x out of pocket max D coinsurance rate, in equation 3 since care costing more than that will exceed your out-of-pocket maximum and you wont pay  <response>: Sorry to break it to you, but uHSASpreadsheetGuy did this a while back. What both this spreadsheet and your calculations do is assume that a deductible must be paid before any health care is paid for, with both an HSA and LDHP. This isnt exactly a true comparison because some services like prescriptions are co-pay only not subject to deductible on LDHPs. If you can anticipate costs, youve got to run it through each plans SBC. 