Free planning tools · Plan servicing and costs

Off-grid toilet running-cost calculator

Put your own prices against ventilation, liners and cover material to plan a year of use.

No account needed. Results update here as you change the inputs. Measurements stay in this tab unless you choose to share a link; shared links contain the inputs, including any location coordinates.

Your inputs

The starting values are examples. Replace them with your own measurements, prices or documented requirements.

What to have ready
  • Occupied days and the ventilation duty required by the model.
  • Your electricity and consumable prices in a single currency.
  • Annual servicing or other recurring costs not covered by the named inputs.
Measurements for Off-grid toilet running-cost calculator

Calculated from your inputs

Your plan

The example will calculate here when JavaScript is ready.

What to do next

    Calculation details

    Inputs used in this result

    Compare a change before committing

    Keep this plan, change the inputs and see the difference. The comparison stays in this tab.

    What will the toilet cost to operate under your usage pattern?

    Separate recurring costs from the purchase price. This toilet running-cost calculator adds ventilation electricity, liners, cover material and other operating costs using the quantities and prices you supply. Set anything your system does not use to zero.

    Compare occasional occupancy with a different annual routine by keeping a baseline in the browser. Use the itemised breakdown to understand a change, then carry the annual figure into the ownership comparison for the complete purchase decision.

    How to use this planner

    1. Choose a currency label; the page does not fetch prices or convert currencies.
    2. Enter your usage and prices, setting unused lines to zero.
    3. Read the annual total and occupied-day equivalent, keeping continuous unattended ventilation in the budget.

    The calculation

    Annual operating cost = fan W × hours/day × occupied days ÷ 1,000 × price/kWh + liners/day × days × price/liner + litres/day × days × price/litre + other annual costs.

    A worked example

    The example inputs total 49.59 per year: 2.59 electricity, 9.00 liners, 18.00 cover material and 20.00 other costs.

    Example inputs are demonstrations. Replace them with your own measurements, prices or documented requirements.

    Assumptions and limits

    All prices are fictional; use one currency throughout. Enter zero for consumables your system does not use. Include unoccupied ventilation days in occupied days if the fan runs year-round, or calculate that electricity separately and add it to other costs. Follow manufacturer ventilation requirements. Purchase, installation, financing and replacement capital equipment are excluded.

    Questions about this calculation

    Is purchase or installation included?

    No. This page isolates operating costs. The ownership comparison adds purchase, installation and replacements over a chosen period using this annual figure.

    How do I include fan use while nobody is staying there?

    The entered fan calculation uses the occupied days. Calculate additional unattended ventilation separately and enter that annual amount under Other, without adding the same energy twice.

    Put the result in context