Free Draft Proofing Calculator: quick draft proofing calculator for everyday decisions. No signup needed.
Everyday utility calculators turn household decisions into transparent estimates with editable assumptions. Choose the local rate, usage, tariff, fee, or comparison inputs that match your situation rather than treating every household topic as electricity consumption or a generic subscription.
Draft proofing begins with the leakage boundary: measure the door and window perimeter that can actually be treated and record whether each opening is used frequently. Separate doors, windows, letterboxes, loft hatches, and service penetrations, because a small gap driven by wind can behave differently from a long perimeter that is already well sealed.
Include compatible seals, brushes, threshold strips, sealant, preparation, access, removal of failed material, and frame repairs in the cost boundary. A cheap strip that prevents a door from closing or traps water can create a new defect. Comfort, noise, dust, and avoided maintenance may matter even when they are not converted into pounds.
Airtightness is not the same as eliminating every air path. Required ventilation, trickle vents, extractor routes, combustion-air supplies, and safe appliance openings must remain appropriate. If the work changes ventilation, condensation, or indoor-air quality, get competent advice rather than treating a lower heating estimate as proof of safety.
Compare normal-season and cold-weather scenarios alongside loft insulation, glazing, wall insulation, and heating controls. Record treated locations, product type, installation date, weather period, and fuel price, because occupancy, tariffs, and weather can change the bill as much as the seal itself.
Measure before and after where practical. A smoke pencil, tissue strip, infrared inspection, or a simple timed observation can help locate a leak, but none of these is a whole-house airtightness certificate. Record wind, temperature, and whether doors or windows were latched during the check. A seal that works in calm weather may perform differently under pressure, and a result from one room should not be generalised to every elevation.
The best intervention may be repair rather than a new strip. A warped door, failed glazing gasket, loose hinge, cracked frame, or damaged threshold can defeat a perimeter calculation. Check opening, escape, drainage, and fire-safety functions after work, and keep ventilation paths clear. If a combustion appliance is present, follow the appliance manufacturer's instructions and obtain competent inspection before changing air paths.
Comfort improvements can be real even when the fuel saving is uncertain. Less cold air, noise, dust, and rattling may affect how a room is used, while a lower bill can also result from milder weather or a changed thermostat. Keep those outcomes separate in the review so the calculator remains an honest planning aid rather than a claim that every observed change came from one seal.
Recheck treated openings after seasonal movement or repainting, because seals can compress, loosen, or become obstructed over time. Keep a dated record of follow-up repairs and weather conditions.
For the next planning step, compare Double Glazing ROI Calculator, Loft Insulation Savings Calculator, and Wall Insulation Calculator. These links stay within the same decision boundary, but each uses different inputs and assumptions. Keep the period, units, eligibility rule, and evidence source visible rather than combining their outputs automatically.
Enter the values you know, keep the units consistent, and change the defaults when your council, provider, property, or household uses different figures. Results are planning estimates, not provider bills or legal determinations.
The formula depends on the topic: Council Tax applies the band multiplier to a local Band D rate; solar export multiplies exported kWh by the tariff; water and waste use volume, frequency, and unit value; comparisons calculate each option independently; rent applies a percentage or fixed increase.
Annual and monthly figures make recurring choices comparable. Payback and ten-year saving are estimates based on the saving you enter, while licensing and council-tax figures should be checked against current official notices.
This is an educational estimate. Council Tax, TV Licensing eligibility and fees, tenancy rules, water charges, and tariffs can change; confirm current details with the relevant official body or provider.