Does a tumble dryer cancel cloth nappy savings in the UK?

What is the only honest way to price a nappy-dry?

There is no official 2026 pence-per-nappy-dry. The lawful figure on the appliance is kWh. Ofgem publishes the electricity unit rate. Multiply them. Standing charges stay on the home whether the drum turns or not — do not add them to the nappy line.

Which? (11 February 2026) lists line-drying instead of tumble-drying as a way to cut reusable-nappy cost, and says tumble-drying increases costs and wears covers faster. It does not publish a dryer kWh table.

How do I turn the dryer label into a nappy-load cost?

1. 1
   Read kWh from the dryer, not from memory The Energy Label and the rating plate give consumption for a stated programme. Use that kWh, or the kWh your smart meter shows for one nappy-dry. Do not invent a 2026 pence figure and work backwards.
2. 2
   Multiply by the unit rate on the bill Example only: 4.8 kWh × 26.32p = 126.3p for that dry at the October–December 2026 Direct Debit average. The same dry at 26.11p is 125.3p. A 2.0 kWh heat-pump programme at 26.32p is 52.6p.
3. 3
   Count only nappy-dry cycles Which? describes washing nappies every two to three days. If you dry that same load in the tumble dryer, that is about 122–183 extra dryer cycles a year on top of household clothes you already dried.
4. 4
   Compare the yearly dryer add-on with the disposable gap you care about MoneyHelper 2024, via Which?, put leading-brand disposables at about £1,000 over 2.5 years and reusables at about £400 including laundry. A supermarket own-brand gap is much smaller — see break-even versus Mamia.

A BBC explainer dated 7 September 2026 quoted typical cycle use at the then current cap of 26.11p/kWh: heat-pump dryers 1.8–2.1 kWh (about 50–56p), condenser 4.5–5.2 kWh (about £1.20–£1.35), vented 4.5–5.3 kWh (about £1.20–£1.40). Those pence travel with the cap. Swap in your label kWh and the newer 26.32p rate from 1 October 2026 if that is the quarter you are in.

How large is the yearly dryer add-on on a nappy rhythm?

Two years of the 4.8 kWh example is about £460 of extra electricity. That can exceed WRAP's 2015 first-baby save band of £200–£500 over 2.5 years, and it can swallow an Aldi-sized gap. It is less likely to swallow MoneyHelper's £600 implied save versus leading-brand disposables over 2.5 years — still a 2024 snapshot, not a promise.

When does the dryer cancel the save?

• Versus Aldi Mamia on one child — a May 2023 retailer sheet already had a £100 terry kit at £348 versus Mamia at £360. Add ~£200-plus of condenser-drying in a year and the cloth column loses on money.
• Damp-house, every-load drying — Mumsnet-style answers that "line-dry and it still beats supermarket disposables; tumble-dry in a damp house and Aldi wins" match the arithmetic even if they are not official.
• Versus branded disposables — the MoneyHelper £1,000 line still leaves room after a heat-pump add-on; a wasteful vented programme eats more of it.
• Wear — Which? says tumble-drying shortens cover life. Extra replacement wraps are a second cash leak, not in the kWh table.

Which? summarises the 2023 Defra life-cycle assessment as: reusable nappies' extra impact is largely electricity for prewashing, washing and tumble-drying. Air-drying is the behaviour that cuts that impact. That is environmental maths, but it tracks the bill.

What if I only tumble-dry in winter?

Price the cycles you actually run. Half a year of 183/2 condenser examples is about £115 at 26.32p/kWh — still enough to matter against Mamia, often not enough to cancel a branded-disposable gap. A heated airer is a separate appliance: the same BBC piece (7 September 2026) put a 300 W airer at about 8p per hour at 26.11p/kWh. Time it, then multiply; do not treat "airer" as zero.

In shortA dryer cancels cloth savings when dryer kWh × Ofgem pence × nappy-dry cycles is larger than the disposable gap you were banking. Read the label. Which? still puts line-drying on the cheap side of the habit list.

What is this page not covering?

• Wash-odour troubleshooting.
• Compression leaks.
• Product-safety judgements — this is a running-cost page.
• A single 2026 pence-per-cycle sold as the national answer.