Sit-ups are scored against the 1-minute sit-up norms from Golding, Myers and Sinning, *The Y's Way to Physical Fitness* (YMCA of the USA), as widely reproduced. The table has six age brackets for each sex: 18-25, 26-35, 36-45, 46-55, 56-65 and 65+. The protocol those norms assume is the one above: knees bent, feet unanchored, hands sliding to the knees, 60 seconds.
Push-ups are scored against a standard push-up rating table with brackets of 17-19, 20-29, 30-39, 40-49, 50-59 and 60-65. The numbers match a table that is widely reproduced online, but its original research source is not documented; Topend Sports, which publishes it, says the original source is unknown. We could not trace it to a named study, so treat it as a practical reference rather than a validated norm. The women's figures used here are for full push-ups, not the modified version from the knees.
Lookup rule: each bracket stores six cut-offs. A count above a cut-off moves you up one tier. For men aged 30-39 the push-up cut-offs are 1, 7, 12, 24, 33 and 41, which gives Very Poor 0-1, Poor 2-7, Below Average 8-12, Average 13-24, Above Average 25-33, Good 34-41, Excellent 42 or more. Where the published table lists the same number at the top of one tier and the bottom of the next, the calculator puts it in the lower tier.
Age handling: push-up ages are held between 17 and 65, so anyone older is rated in the 60-65 bracket. Sit-up ages are held between 18 and 70; a 17-year-old is rated in the 18-25 bracket and anyone 66 or older in the 65+ bracket.