Billable hours, man-day conversions, engagement totals - precise to the minute, formatted for the ledger.
Time billing lives and dies on the h:mm → decimal conversion: 38h 45m must invoice as 38.75, and a "day" in your engagement model is 8 hours, not 24. TCalc handles both - instant decimal output, and custom converters that know a working day from a calendar day.
Total a team's week in one expression and read it back in whichever unit the report wants.
Time gets recorded in hours and invoiced in whatever unit the engagement letter specifies, and those are rarely the same. Man-days are the common case: the convention is that one man-day is eight hours, so 120 recorded hours is fifteen man-days. Where clients differ is the divisor - some engagements run on seven-and-a-half-hour days - so the conversion should be a stated ratio rather than a habit.
Full-time equivalent works the same way one level up. FTE expresses a workload as a fraction of a full-time week, normally forty hours, so thirty hours is 0.75 FTE. Both conversions are simple division; both are also exactly the kind of repeated manual step where a transposed digit survives all the way to an invoice.
A day of billable entries totalled without decimal drift.
Recorded hours converted to man-days for invoicing.
A part-time workload expressed as an FTE fraction.
Annual billable capacity is the starting point for any resourcing conversation, and it is a subtraction: the nominal working year less leave, less public holidays, less any non-billable allowance. Starting from 2,080 hours and removing twenty days of leave and ten public holidays leaves 1,840 hours, and that is the number a utilisation target should be measured against rather than the headline figure.
On a live engagement the more urgent question is when the budget runs out. Subtract logged time from the budget to get the remaining hours, divide by the daily rate of burn to get working days, and add those to today to get a calendar date. That date is the thing worth putting in front of a client, because it converts an abstract overrun into a deadline.
Annual billable capacity after twenty leave days and ten public holidays.
Budget remaining on an engagement after three months of logged time.
Sixty-five hours at eight a day, expressed as the calendar date it runs out.
A ratio conversion divides by a single factor: hours to man-days is one division by eight, and it behaves predictably at every scale. A step conversion chains several factors, and that is where intuition fails. Converting a calendar week to work hours is not one division - it is weeks to five-day weeks, then days to eight-hour days, giving forty hours rather than the 168 a naive conversion produces.
Knowing which kind you are applying matters because the two disagree by a factor of more than four on exactly the input people use most often. Quoting a month of work as 720 hours instead of 160 is not a rounding error; it is a different proposal.
A standard month of capacity, stepped through work days rather than calendar days.
One calendar week as work hours - not 168.
Engagement total as invoice-ready decimal.
Duration to total hours in one tap.
Three staff days totalled.
Hours back to days - and with custom converters, a day can be 8h.
Divide minutes by 60: 38h 45m = 38.75 hours. TCalc shows any duration as decimal hours with one tap on the output format.
Yes - the built-in conversion treats a day as 24h (36h = 1.5D), and custom converters let you define a working day as 8h so 1 week = 40 hours, matching how engagements are actually billed.
Yes - TCalc keeps full precision (down to seconds and beyond); 6 minutes is 0.1h and totals never drift from rounding.