What is an equipment histogram?
An equipment histogram is a bar chart of how many machines a project needs over time: time runs along the bottom and the number of units up the side, with one color for each type of equipment. Mastt describes the resource histogram the same way and notes the pattern of phased projects: a gradual build-up, a peak, then planned demobilization.
Contractors use it to agree the equipment plan with the client, book hired plant ahead of the peak, and see when machines should leave site. Adding the actual dates turns the plan into a weekly check of what is really on site.
How to use the equipment plan and histogram
- Set up the project: name, start date (week 1 starts on it), currency, working days a week and how many days ahead you want the mobilization notice.
- Enter the plan: one row per machine or group of identical machines, with the planned on-site and off-site dates from the program of works.
- Enter the rate: monthly, weekly, daily or hourly, as in the hire agreement, or an internal rate for your own machines.
- Review the histogram and the budget with the planning and commercial teams before you place hire orders.
- Record the actual dates from delivery and return notes, or from the tracking system, as each machine arrives and leaves.
- Review the statuses every week: chase late arrivals, and return or reassign machines past their off-site date.
How does the template calculate the histogram and the cost?
The monthly cost spreads each row over the calendar days it falls in each month. Statuses compare the dates with the as-of date: a machine with no actual on-site date after its planned date is late, and a machine still on site after its planned off-site date is overdue.
Source for the histogram method: Arlene Hidalgo, What Is a Resource Histogram?, Mastt, 3 March 2025. Source: Mastt. Last reviewed 21 October 2026.
Worked example: a roads and earthworks package
The example rows start on 6 September 2026 and use rates in USD that are illustrations, not market rates. On 21 October 2026:
- The plan peaks at 20 units in the week starting 6 December 2026, when the tower crane joins the earthworks fleet. 16 units are on site on 21 October.
- Two excavators at 10,000 a month cost 10,000 × 12 ÷ 365 = 328.77 a day each. Over the 169 planned days that is 2 × 328.77 × 169 = 111,123.
- The 50 t mobile crane at 1,200 a day, six working days a week, costs 1,028.57 a calendar day. It was due off site on 15 October and is still there: 6 days overdue, 6,171 so far.
- The two rollers were due on 18 October and have not arrived: Mobilization late, 3 days. The concrete pump is due on 25 October: Mobilizing soon.
- The total planned cost is 981,393, with the highest month in December 2026.
Common mistakes with equipment plans
- Planning by type only. Without a row per machine or group you cannot follow arrivals, returns and costs.
- Never entering actual dates. The plan then shows what was intended, not what is on site and being paid for.
- Keeping hired plant past its dates. Machines that finished their work keep costing hire until someone returns them.
- Mixing rate bases. A daily rate written in the monthly column inflates the budget many times over.
- One histogram for the whole contract. Large projects need a plan per package or zone, then a combined view.
What the template does not do
The template counts and costs machines from the dates and rates you enter; it does not schedule the work or check that a machine is idle. Planned cost leaves out fuel, operators and mobilization charges unless your rate includes them. A week counts a machine on site on any day of it, so short stays show as full weeks. The charts show the 15 listed equipment types; types you add in empty rows appear in the tables. To estimate how many machines a quantity needs, use the Excavator, Loader & Dozer Productivity Calculator, and to check daily hours and hire invoices, use the Equipment Timesheet and Hours Reconciliation Template.