ACT Rent Increase Calculator

(function () { "use strict"; /* ============================================================ CPI DATA - Canberra rents sub-index, ABS Consumer Price Index Source (as supplied to ACT Shelter): Table 9, CPI Group/Sub- group/Expenditure Class, Index Numbers by Capital City. >>> ADD A NEW LINE HERE EACH MONTH when the ABS releases a new >>> figure. Keep the list in date order. Then update >>> LAST_UPDATED below. That is the only maintenance this file >>> needs. ============================================================ */ var CPI_DATA = [ { month: "Aug 2022", value: 95.35 }, { month: "Sep 2022", value: 95.67 }, { month: "Oct 2022", value: 95.95 }, { month: "Nov 2022", value: 96.43 }, { month: "Dec 2022", value: 96.72 }, { month: "Jan 2023", value: 97.07 }, { month: "Feb 2023", value: 97.39 }, { month: "Mar 2023", value: 97.68 }, { month: "Apr 2023", value: 97.87 }, { month: "May 2023", value: 98.08 }, { month: "Jun 2023", value: 98.59 }, { month: "Jul 2023", value: 98.71 }, { month: "Aug 2023", value: 98.82 }, { month: "Sep 2023", value: 98.65 }, { month: "Oct 2023", value: 98.23 }, { month: "Nov 2023", value: 98.33 }, { month: "Dec 2023", value: 98.80 }, { month: "Jan 2024", value: 98.92 }, { month: "Feb 2024", value: 99.07 }, { month: "Mar 2024", value: 99.03 }, { month: "Apr 2024", value: 99.04 }, { month: "May 2024", value: 99.28 }, { month: "Jun 2024", value: 99.36 }, { month: "Jul 2024", value: 99.45 }, { month: "Aug 2024", value: 99.52 }, { month: "Sep 2024", value: 99.35 }, { month: "Oct 2024", value: 99.01 }, { month: "Nov 2024", value: 99.28 }, { month: "Dec 2024", value: 99.37 }, { month: "Feb 2025", value: 99.60 }, { month: "Mar 2025", value: 99.65 }, { month: "Apr 2025", value: 99.70 }, { month: "May 2025", value: 99.79 }, { month: "Jun 2025", value: 99.83 }, { month: "Jul 2025", value: 99.90 }, { month: "Aug 2025", value: 99.98 }, { month: "Sep 2025", value: 100.00 }, { month: "Oct 2025", value: 100.01 }, { month: "Nov 2025", value: 100.32 }, { month: "Dec 2025", value: 100.43 }, { month: "Jan 2026", value: 100.55 }, { month: "Feb 2026", value: 100.71 }, { month: "Mar 2026", value: 100.77 }, { month: "Apr 2026", value: 100.77 } ]; // NOTE: Jan 2025 is missing from the source table supplied to ACT // Shelter - check this against the official ABS spreadsheet before // publishing live. May 2026 is due for release 24/6/2026 and isn't // included yet. var LAST_UPDATED = "18 June 2026"; document.getElementById("arc-last-updated").textContent = "CPI figures in this tool last checked: " + LAST_UPDATED + "."; // Populate the two index dropdowns from CPI_DATA (most recent first) var initialSel = document.getElementById("arc-initial-index"); var currentSel = document.getElementById("arc-current-index"); for (var i = CPI_DATA.length - 1; i >= 0; i--) { var row = CPI_DATA[i]; var optA = document.createElement("option"); optA.value = row.value; optA.textContent = row.month + " \u2014 " + row.value.toFixed(2); initialSel.appendChild(optA); var optB = document.createElement("option"); optB.value = row.value; optB.textContent = row.month + " \u2014 " + row.value.toFixed(2); currentSel.appendChild(optB); } // Default "current" to the most recently available figure currentSel.value = CPI_DATA[CPI_DATA.length - 1].value; // Element refs var rentEl = document.getElementById("arc-rent"); var freqEl = document.getElementById("arc-freq"); var refDateEl = document.getElementById("arc-ref-date"); var refDateLabel = document.getElementById("arc-ref-date-label"); var noticeDateEl = document.getElementById("arc-notice-date"); var effectiveDateEl = document.getElementById("arc-effective-date"); var proposedRentEl = document.getElementById("arc-proposed-rent"); var alertsEl = document.getElementById("arc-alerts"); var resultEl = document.getElementById("arc-result"); function radioValue(name) { var els = document.getElementsByName(name); for (var i = 0; i < els.length; i++) if (els[i].checked) return els[i].value; return null; } // Toggle the reference-date label between "tenancy began" / "last increase notice" document.getElementsByName("arc-hasinc").forEach(function (el) { el.addEventListener("change", function () { refDateLabel.textContent = radioValue("arc-hasinc") === "yes" ? "Date you were given notice of your last rent increase" : "Date your tenancy began"; recalc(); }); }); function fmtMoney(n) { var sign = n < 0 ? "-" : ""; return sign + "$" + Math.abs(n).toFixed(2); } function addMonths(date, months) { var d = new Date(date.getTime()); d.setMonth(d.getMonth() + months); return d; } function daysBetween(a, b) { return Math.round((b.getTime() - a.getTime()) / 86400000); } function parseDate(input) { if (!input.value) return null; var parts = input.value.split("-"); return new Date(parseInt(parts[0], 10), parseInt(parts[1], 10) - 1, parseInt(parts[2], 10)); } function recalc() { var alerts = []; var rent = parseFloat(rentEl.value); var initial = parseFloat(initialSel.value); var current = parseFloat(currentSel.value); var refDate = parseDate(refDateEl); var noticeDate = parseDate(noticeDateEl); var effectiveDate = parseDate(effectiveDateEl); var pretransition = radioValue("arc-pretransition"); if (pretransition === "yes") { alerts.push({ type: "stop", title: "This calculator doesn\u2019t apply to your tenancy", body: "Fixed-term agreements that started before 10 December 2024 follow the rent-increase terms in the tenancy agreement itself, not the CPI formula. Check your agreement, or contact the Tenants\u2019 Union ACT or Legal Aid ACT for help reading it." }); renderAlerts(alerts); resultEl.innerHTML = '

No calculation shown \u2014 see the note above.

'; return; } if (refDate && effectiveDate) { var minDate = addMonths(refDate, 12); if (effectiveDate < minDate) { alerts.push({ type: "warn", title: "Less than 12 months since the last increase (or tenancy start)", body: "Landlords can only increase rent once every 12 months. Based on the dates entered, the earliest this increase could take effect is " + minDate.toLocaleDateString("en-AU") + "." }); } } if (noticeDate && effectiveDate) { var minNotice = new Date(noticeDate.getTime()); minNotice.setDate(minNotice.getDate() + 56); if (effectiveDate < minNotice) { alerts.push({ type: "warn", title: "Less than 8 weeks\u2019 written notice", body: "At least 8 weeks\u2019 notice is required. Based on the dates entered, the earliest valid effective date would be " + minNotice.toLocaleDateString("en-AU") + "." }); } } renderAlerts(alerts); if (!rent || !initial || !current) { resultEl.innerHTML = '

Fill in the rent amount and both CPI figures above to see the maximum allowed increase.

'; return; } var growth = (current - initial) / initial; var prescribedAmountRaw = 1.1 * rent * growth; var prescribedAmount = Math.max(0, prescribedAmountRaw); var maxRent = rent + prescribedAmount; var pct = (prescribedAmount / rent) * 100; var freqLabel = freqEl.value === "week" ? "per week" : freqEl.value === "fortnight" ? "per fortnight" : "per month"; var html = ""; html += ''; html += ''; if (prescribedAmountRaw <= 0) { html += ''; } else if (proposedRentEl.value) { var proposed = parseFloat(proposedRentEl.value); if (proposed <= maxRent + 0.005) { html += ''; } else { html += ''; } } resultEl.innerHTML = html; } function renderAlerts(alerts) { alertsEl.innerHTML = alerts.map(function (a) { return ''; }).join(""); } [rentEl, freqEl, refDateEl, noticeDateEl, effectiveDateEl, proposedRentEl, initialSel, currentSel].forEach(function (el) { el.addEventListener("input", recalc); el.addEventListener("change", recalc); }); document.getElementsByName("arc-pretransition").forEach(function (el) { el.addEventListener("change", recalc); }); recalc(); })();