Project planning guide
List the work, estimate the hours for each task, then add an explicit buffer and rate. Change one assumption to see what moves; keep unknown scope visible instead of hiding it inside a confident total.
List the work included in the estimate, then write down how many hours each task may take. A task count multiplied by hours per task gives a starting point, but it says nothing about work that has not been identified. Name exclusions and open questions beside the number.
The example uses eight tasks at three hours each: 24 base hours. A 25% buffer adds six hours, making 30 hours. The percentage is an illustrative planning assumption, not a standard allowance. Increase or remove it to see how sensitive the result is.
At an example rate of $75 per hour, 30 hours yields $2,250. Changing the task count from eight to ten makes 37.5 hours and $2,812.50 under the same buffer and rate. The change adds $562.50; it does not prove that the scope is complete.
Decide what change would require a new quote or conversation: another task, a rate change, or a larger uncertainty. Keep the original estimate and its assumptions so the reason for the revision is clear.
Editable example
This source uses the shipped plain-text calculation syntax. Copy it into a Continuum scratchpad, then change tasks, hours, buffer, or rate.
# Project estimate: illustrative currency and rate
tasks = 8
hours_per_task = 3
base_hours = tasks * hours_per_task
buffer = 25% of base_hours
total_hours = base_hours + buffer
hourly_rate = 75 in usd
estimated_cost = total_hours * hourly_rateThe currency and rate are illustrative. Opening Continuum does not import this example; paste the copied source into a local document when you are ready.
Worked result
The estimate moves from $2,250 to $2,812.50. This is arithmetic on stated inputs, not a forecast of the final project cost.
Questions
There is no universal percentage. Use a stated allowance tied to what is unknown, and revise it when the scope becomes clearer.
It gives an illustrative time-based cost. A fixed quote also needs scope, risk, commercial terms, and a decision about who absorbs changes.
No. Copying only places the source on your clipboard. Open the scratchpad and paste it if you want to work with it locally.
Keep the reasoning
Paste the example into a free local scratchpad and change the assumptions as the project becomes clearer.
Open the free scratchpad