Calculator updates

7 September 2026 — v3.6.18

U-Value Pro framing UI cleanup: fixed the single metal-stud wall state so second-frame size and clear-gap controls are hidden unless Twin wall is selected. Simplified the MF ceiling below concrete soffit workflow by removing suspended void depth and insulation-position controls; users now choose insulation thickness and plasterboard layers only, while the MF thermal-bridge caveat remains visible.

26 August 2026 — v3.6.17

U-Value PDF Android reliability update: replaced the hidden-section print method with a dedicated rendered report document. Print / Save PDF now opens an actual visible A4 calculation report first and prints that document, avoiding Android/Samsung print services returning a blank page when content depends on print-only CSS.

26 August 2026 — v3.6.16

U-Value PDF mobile print fix: corrected the print-only layout selector that could produce a blank A4 preview on Android/Samsung print services. The professional calculation sheet is now explicitly exposed and painted before the browser print dialog opens.

26 August 2026 — v3.6.15

Professional U-Value PDF report: added a dedicated A4 calculation-report view with optional project, element/reference and prepared-by details; ordered construction layers; thickness, λ/R inputs and calculated R-values; surface resistances; calculation method and corrections; metal stud/MF system details; named-product source references; design-target status; and calculation assumptions. Print / Save PDF now produces a calculation sheet rather than a webpage printout.

26 August 2026 — v3.6.14

U-Value Pro layer ordering + MF soffit ceilings: added up/down controls to every construction layer so build-ups can be reordered without deleting and recreating materials. Added a Concrete soffit + insulated MF ceiling quick build-up with adjustable suspended void, insulation position/thickness and plasterboard layers, plus target-solver feedback on whether the recommended insulation thickness fits the selected MF void.

26 August 2026 — v3.6.13

U-Value Pro verified product expansion: added ROCKWOOL Thermal Insulation Roll and Rollbatt; Knauf Loft Roll 40/44; Superglass Multi-Roll 40/44; Isover Acoustic Partition Roll APR 1200; and Knauf Rocksilk Soffit Linerboard Standard/Extra. The database now supports thickness-specific declared lambda values, used for Isover APR 1200 where λ varies by product thickness.

26 August 2026 — v3.6.12

U-Value target solver fix: corrected insulation-layer detection so named manufacturer products such as ROCKWOOL Soffit Slab, Kingspan Thermawall and Knauf/ROCKWOOL slabs are recognised by the reverse thickness solver. Soffit build-ups now populate the insulation selector correctly and retain practical product-thickness recommendations.

26 August 2026 — v3.6.11

U-Value Pro soffit + twin metal walls: added a concrete soffit/floor-over-unheated-space calculation with ROCKWOOL Soffit Slab (declared λ 0.034 W/mK and stored common thicknesses), plus single/twin metal stud wall controls. Twin walls can use independent 50, 70, 90 or 146 mm stud depths with a selectable clear gap; the calculator totals the available insulated void and the target solver now reports whether its suggested insulation thickness physically fits that void.

26 August 2026 — v3.6.9

U-Value Pro materials + target solver: expanded the material library with grouped generic insulation classes and verified UK products with source links, added common product thickness data, and introduced a reverse target-U-value solver that calculates the theoretical insulation requirement and suggests the next practical thickness. The solver supports uniform and timber repeating-bridge calculations and deliberately warns rather than inventing a precise answer for metal-framed thermal bridging.

26 August 2026 — v3.6.8

U-Value Pro metal stud update: added Metal stud partition as a framed-wall option with 50, 70, 90 and 146 mm C-stud sizes plus 400/600 mm centres. Timber frame remains available. Metal framing is clearly distinguished from timber repeating-bridge calculations so the tool does not imply false precision for steel thermal bridging.

26 August 2026 — v3.6.6

Compound Interest lump sums: added optional one-off contributions to the Compound Interest Calculator. Users can add multiple lump sums, choose the year for each, remove them individually, and see additional lump sums separated from regular contributions in the result. Lump sums are modelled at the start of the selected year and are included in sensitivity scenarios.

20 August 2026 — v3.6.5

Date selector polish: refined the active date-mode styling so the copper border is an even 1px around the full selector, removing the heavier left-hand accent while retaining the subtle selected tint.

20 August 2026 — v3.6.4

Date mode & mobile focus polish: fixed the selected-state logic for Between two dates / Date in the future / Date in the past, replaced the heavy selected label with a subtle copper edge and tint, and moved homepage search focus styling from the square input itself to the full rounded search control.

19 August 2026 — v3.6.3

Date Calculator UX: made the selected date-calculator mode unmistakable on mobile and desktop with the Calculate This copper accent, a subtle selected-state treatment and a visible Selected label. Tightened the mobile mode controls and improved keyboard focus/state handling.

19 August 2026 — v3.6.2

Advanced Date Calculator: future and past date modes now accept either days or weeks. Calendar weeks use 7 days; working weeks use 5 working days and continue to skip weekends and the selected UK region's official bank holidays.

19 August 2026 — v3.6.1

Advanced Date Calculator: expanded Days Between Dates with calendar/working-day modes, official UK bank-holiday exclusions for England & Wales, Scotland and Northern Ireland, plus tools to add or subtract calendar or working days from any chosen date.

15 August 2026 — v3.6.0

Search Console growth pass: used real Google Search performance data to strengthen Fuel Cost, Percentage Change, Loan Repayment, Metal Stud Wall and Monthly Savings pages around the search intent Google is already testing. Added useful worked examples and clearer page language without keyword stuffing or site-wide title churn. The Updates page was also redesigned to match the rest of Calculate This.

14 August 2026 — v3.5.3

Accessibility & UX QA: added skip-to-content navigation and strong keyboard focus states site-wide, improved result announcements and invalid-number semantics, added labels to text tools and dynamic U-value controls, enabled keyboard navigation for tabbed calculator modes, standardised button behaviour and mobile numeric keyboards, improved table/result overflow on small screens, and moved related-calculator sections inside the main page landmark where required.

13 August 2026 — v3.5.1

Internal linking & discovery: added curated Related calculators sections across 96 calculator pages using crawlable HTML links and descriptive calculator names. Priority journeys connect closely related tools such as Mortgage → Stamp Duty/LTV, Metal Stud → Plasterboard/Insulation/MF Ceiling, and BMI → Calorie/Macro/Protein/Water.

13 August 2026 — v3.4.4

Financial trust pass: VAT now shows current UK VAT rates, a worked example and GOV.UK sources. Mortgage and Loan calculators now show ±1 percentage-point repayment sensitivity and clearer assumptions. Compound Interest now shows ±2 percentage-point growth scenarios and explicitly states the compounding, contribution timing and exclusions behind the projection.

13 August 2026 — v3.4.3

Construction accuracy pass: Plasterboard now supports one or two layers per face and 3000 × 600 boards; Insulation separates net and ordering area; Screed and Concrete clearly separate net volume from ordering allowance; Brick & Block now allows significant openings to be deducted before waste is applied. Printable assumptions were updated to match.

13 August 2026 — v3.4.2

Metal Stud Partition Calculator: every single or double door opening now adds one additional full-height whipper/support stud to the stud order. The extra stud is also included when comparing the most efficient stud stock length.

13 August 2026

MF Ceiling Calculator: waste allowance now carries through to MF5, MF6 and MF7. MF7 take-off now uses explicit channel runs at maximum 1200mm centres and includes the edge run.

Ceiling Tile Calculator: 600 × 600 grid now reports 1200mm and 600mm cross tees separately; 1200 × 600 tiles use 1200mm cross tees only.

12 August 2026

Salary Calculator: 2026/27 Income Tax, Scottish Income Tax and employee Class 1 NI rates checked against HMRC/GOV.UK. Added visible rate tables, sources and a worked example.

Stamp Duty Calculator: residential SDLT rates checked against HMRC/GOV.UK. Added the 2% non-UK-resident surcharge option, visible rate table, sources and a worked example.

How updates work

Rule-dependent calculators are reviewed when a new tax year, published rate change or material rule change affects their result. The relevant calculator page shows when its rates were last checked and links to the official source used.