diff --git a/ts/src/stats/IntervalsGraph.svelte b/ts/src/stats/IntervalsGraph.svelte
index 5fedf49a6..90344aca6 100644
--- a/ts/src/stats/IntervalsGraph.svelte
+++ b/ts/src/stats/IntervalsGraph.svelte
@@ -1,23 +1,16 @@
 <script lang="typescript">
-    import {
-        gatherIntervalData,
-        intervalGraph,
-        IntervalUpdateFn,
-        IntervalRange,
-    } from "./intervals";
+    import { defaultGraphBounds } from "./graphs";
+
+    import { gatherIntervalData, intervalGraph, IntervalRange } from "./intervals";
     import type { IntervalGraphData } from "./intervals";
     import { onMount } from "svelte";
     import pb from "../backend/proto";
 
+    const bounds = defaultGraphBounds();
+
     export let data: pb.BackendProto.GraphsOut | null = null;
 
     let svg = null as HTMLElement | SVGElement | null;
-    let updater = null as IntervalUpdateFn | null;
-
-    onMount(() => {
-        updater = intervalGraph(svg as SVGElement);
-    });
-
     let range = IntervalRange.Percentile95;
 
     let intervalData: IntervalGraphData | null = null;
@@ -26,8 +19,8 @@
         intervalData = gatherIntervalData(data);
     }
 
-    $: if (intervalData && updater) {
-        updater(intervalData, range);
+    $: if (intervalData) {
+        intervalGraph(svg as SVGElement, bounds, intervalData, range);
     }
 </script>
 
@@ -60,7 +53,25 @@
         </label>
     </div>
 
-    <svg bind:this={svg}>
+    <svg bind:this={svg} viewBox={`0 0 ${bounds.width} ${bounds.height}`}>
+        <g class="bars" />
+        <g class="hoverzone" />
         <path class="area" />
+        <g
+            class="x-ticks no-domain-line"
+            transform={`translate(0,${bounds.height - bounds.marginBottom})`} />
+        <g
+            class="y-ticks no-domain-line"
+            transform={`translate(${bounds.marginLeft}, 0)`} />
+        <text
+            class="axis-label"
+            transform={`translate(${bounds.width / 2}, ${bounds.height - 5})`}>
+            Interval (days)
+        </text>
+        <text
+            class="axis-label y-axis-label"
+            transform={`translate(${bounds.marginLeft / 3}, ${(bounds.height - bounds.marginBottom) / 2 + bounds.marginTop}) rotate(-180)`}>
+            Number of cards
+        </text>
     </svg>
 </div>
diff --git a/ts/src/stats/graphs.css b/ts/src/stats/graphs.css
index c8e10b34f..02b0f64e9 100644
--- a/ts/src/stats/graphs.css
+++ b/ts/src/stats/graphs.css
@@ -54,5 +54,20 @@
 .intervals .area {
     opacity: 0.05;
     pointer-events: none;
-    stroke: black;
+    fill: #555;
+}
+
+.axis-label {
+    text-anchor: middle;
+    font-size: 10px;
+}
+
+.y-axis-label {
+    writing-mode: vertical-rl;
+    rotate: 180;
+}
+
+.hoverzone rect {
+    fill: none;
+    pointer-events: all;
 }
diff --git a/ts/src/stats/graphs.ts b/ts/src/stats/graphs.ts
index 1166a8ece..eb8e59267 100644
--- a/ts/src/stats/graphs.ts
+++ b/ts/src/stats/graphs.ts
@@ -39,3 +39,23 @@ export enum GraphRange {
     Year = 2,
     All = 3,
 }
+
+export interface GraphBounds {
+    width: number;
+    height: number;
+    marginLeft: number;
+    marginRight: number;
+    marginTop: number;
+    marginBottom: number;
+}
+
+export function defaultGraphBounds(): GraphBounds {
+    return {
+        width: 600,
+        height: 250,
+        marginLeft: 100,
+        marginRight: 20,
+        marginTop: 20,
+        marginBottom: 40,
+    };
+}
diff --git a/ts/src/stats/intervals.ts b/ts/src/stats/intervals.ts
index f7a6f15a9..56127f733 100644
--- a/ts/src/stats/intervals.ts
+++ b/ts/src/stats/intervals.ts
@@ -4,20 +4,19 @@
 /* eslint
 @typescript-eslint/no-non-null-assertion: "off",
 @typescript-eslint/no-explicit-any: "off",
-@typescript-eslint/ban-ts-ignore: "off",
-@typescript-eslint/explicit-function-return-type: "off" */
+ */
 
-import { select, mouse, Selection } from "d3-selection";
+import "d3-transition";
+import pb from "../backend/proto";
+import { select, mouse } from "d3-selection";
 import { cumsum, extent, max, histogram, quantile } from "d3-array";
 import { interpolateBlues } from "d3-scale-chromatic";
 import { scaleLinear, scaleSequential } from "d3-scale";
 import { axisBottom, axisLeft } from "d3-axis";
 import { area } from "d3-shape";
-import "d3-transition";
 import { CardQueue } from "../cards";
 import { showTooltip, hideTooltip } from "./tooltip";
-import pb from "../backend/proto";
-import { assertUnreachable } from "../typing";
+import { GraphBounds } from "./graphs";
 
 export interface IntervalGraphData {
     intervals: number[];
@@ -38,199 +37,138 @@ export function gatherIntervalData(data: pb.BackendProto.GraphsOut): IntervalGra
     return { intervals };
 }
 
-export type IntervalUpdateFn = (
-    arg0: IntervalGraphData,
+export function intervalGraph(
+    svgElem: SVGElement,
+    bounds: GraphBounds,
+    graphData: IntervalGraphData,
     maxDays: IntervalRange
-) => void;
+): void {
+    const svg = select(svgElem);
+    const trans = svg.transition().duration(600) as any;
 
-/// Creates an interval graph, returning a function used to update it.
-export function intervalGraph(svgElem: SVGElement): IntervalUpdateFn {
-    const margin = { top: 20, right: 20, bottom: 40, left: 100 };
-    const height = 250;
-    const width = 600;
-    const xTicks = 6;
+    const allIntervals = graphData.intervals;
 
-    // svg elements
-    const svg = select(svgElem).attr("viewBox", [0, 0, width, height].join(" "));
-    const barGroup = svg.append("g");
-    const hoverGroup = svg.append("g");
-    const areaPath = svg.select("path.area");
-    const xAxisGroup = svg.append("g").classed("no-domain-line", true);
-    const yAxisGroup = svg.append("g").classed("no-domain-line", true);
+    const [xMin, origXMax] = extent(allIntervals);
+    let xMax = origXMax;
+    switch (maxDays) {
+        case IntervalRange.Month:
+            xMax = Math.min(xMax!, 31);
+            break;
+        case IntervalRange.Percentile50:
+            xMax = quantile(allIntervals, 0.5);
+            break;
+        case IntervalRange.Percentile95:
+            xMax = quantile(allIntervals, 0.95);
+            break;
+        case IntervalRange.Percentile999:
+            xMax = quantile(allIntervals, 0.999);
+            break;
+        case IntervalRange.All:
+            break;
+    }
+    const desiredBars = Math.min(70, xMax! - xMin!);
 
-    // x axis
-    const xScale = scaleLinear()
-        .range([margin.left, width - margin.right])
-        .domain([0, 0]);
-    svg.append("text")
-        .attr("transform", `translate(${width / 2}, ${height - 5})`)
-        .style("text-anchor", "middle")
-        .style("font-size", 10)
-        .text("Interval (days)");
+    // x scale & bins
 
-    // y axis
-    const yScale = scaleLinear()
-        .domain([0, 0])
-        .range([height - margin.bottom, margin.top]);
-    svg.append("text")
-        .attr(
-            "transform",
-            `translate(${margin.left / 3}, ${
-                (height - margin.bottom) / 2 + margin.top
-            }) rotate(-180)`
-        )
-        .style("text-anchor", "middle")
-        .style("writing-mode", "vertical-rl")
-        .style("rotate", "180")
-        .style("font-size", 10)
-        .text("Number of cards");
+    const x = scaleLinear()
+        .range([bounds.marginLeft, bounds.width - bounds.marginRight])
+        .domain([xMin!, xMax!]);
+    const data = histogram()
+        .domain(x.domain() as any)
+        .thresholds(x.ticks(desiredBars))(allIntervals);
+    svg.select<SVGGElement>(".x-ticks")
+        .transition(trans)
+        .call(axisBottom(x).ticks(6).tickSizeOuter(0));
 
-    function update(graphData: IntervalGraphData, maxDays: IntervalRange) {
-        const allIntervals = graphData.intervals;
+    // y scale
 
-        const [xMin, origXMax] = extent(allIntervals);
+    const yMax = max(data, (d) => d.length);
+    const y = scaleLinear()
+        .range([bounds.height - bounds.marginBottom, bounds.marginTop])
+        .domain([0, yMax!]);
+    svg.select<SVGGElement>(".y-ticks")
+        .transition(trans)
+        .call(
+            axisLeft(y)
+                .ticks(bounds.height / 80)
+                .tickSizeOuter(0)
+        );
 
-        let desiredBars = 70;
-        let xMax = origXMax;
-        switch (maxDays) {
-            case IntervalRange.Month:
-                xMax = Math.min(xMax!, 31);
-                desiredBars = 31;
-                break;
-            case IntervalRange.Percentile50:
-                xMax = quantile(allIntervals, 0.5);
-                break;
-            case IntervalRange.Percentile95:
-                xMax = quantile(allIntervals, 0.95);
-                break;
-            case IntervalRange.Percentile999:
-                xMax = quantile(allIntervals, 0.999);
-                break;
-            case IntervalRange.All:
-                break;
-            default:
-                assertUnreachable(maxDays);
-        }
+    // x bars
 
-        const x = xScale.copy().domain([xMin!, xMax!]);
-        // .nice();
-
-        const data = histogram()
-            .domain(x.domain() as any)
-            .thresholds(x.ticks(desiredBars))(allIntervals);
-
-        const yMax = max(data, (d) => d.length);
-
-        const colourScale = scaleSequential(interpolateBlues).domain([
-            -20,
-            data.length,
-        ]);
-
-        const y = yScale.copy().domain([0, yMax!]);
-
-        const t = svg.transition().duration(600);
-
-        const updateXAxis = (
-            g: Selection<SVGGElement, unknown, null, undefined>,
-            scale: any
-        ) =>
-            g
-                .attr("transform", `translate(0,${height - margin.bottom})`)
-                .call(axisBottom(scale).ticks(xTicks).tickSizeOuter(0));
-
-        xAxisGroup.transition(t as any).call(updateXAxis as any, x);
-
-        const updateYAxis = (
-            g: Selection<SVGGElement, unknown, null, undefined>,
-            scale: any
-        ) =>
-            g.attr("transform", `translate(${margin.left}, 0)`).call(
-                axisLeft(scale)
-                    .ticks(height / 80)
-                    .tickSizeOuter(0)
-            );
-
-        yAxisGroup.transition(t as any).call(updateYAxis as any, y);
-
-        function barWidth(d: any): number {
-            const width = Math.max(0, x(d.x1) - x(d.x0) - 1);
-            return width ? width : 0;
-        }
-
-        const updateBar = (sel: any) => {
-            return sel.call((sel) =>
-                sel
-                    .transition(t as any)
-                    .attr("width", barWidth)
-                    .attr("x", (d: any) => x(d.x0))
-                    .attr("y", (d: any) => y(d.length)!)
-                    .attr("height", (d: any) => y(0) - y(d.length))
-                    .attr("fill", (d, idx) => colourScale(idx))
-            );
-        };
-
-        barGroup
-            .selectAll("rect")
-            .data(data)
-            .join(
-                (enter) =>
-                    updateBar(
-                        enter
-                            .append("rect")
-                            .attr("rx", 1)
-                            .attr("x", (d: any) => x(d.x0))
-                            .attr("y", y(0))
-                            .attr("height", 0)
-                    ),
-                (update) => updateBar(update),
-                (remove) =>
-                    remove.call((remove) =>
-                        remove
-                            .transition(t as any)
-                            .attr("height", 0)
-                            .attr("y", y(0))
-                    )
-            );
-
-        const areaData = cumsum(data.map((d) => d.length));
-        const xAreaScale = x.copy().domain([0, areaData.length]);
-        const yAreaScale = y.copy().domain([0, allIntervals.length]);
-
-        areaPath
-            .datum(areaData as any)
-            .attr("fill", "grey")
-            .attr(
-                "d",
-                area()
-                    .x((d: any, idx) => {
-                        return xAreaScale(idx);
-                    })
-                    .y0(height - margin.bottom)
-                    .y1((d: any) => yAreaScale(d)) as any
-            );
-
-        hoverGroup
-            .selectAll("rect")
-            .data(data)
-            .join("rect")
-            .attr("x", (d: any) => x(d.x0))
-            .attr("y", () => y(yMax!))
-            .attr("width", barWidth)
-            .attr("height", () => y(0) - y(yMax!))
-            .attr("fill", "none")
-            .attr("pointer-events", "all")
-            .on("mousemove", function (this: any, d: any, idx) {
-                const [x, y] = mouse(document.body);
-                const pct = ((areaData[idx] / allIntervals.length) * 100).toFixed(2);
-                showTooltip(
-                    `${d.length} cards with interval ${d.x0}~${d.x1} days. ` +
-                        `<br>${pct}% cards below this point.`,
-                    x,
-                    y
-                );
-            })
-            .on("mouseout", hideTooltip);
+    function barWidth(d: any): number {
+        const width = Math.max(0, x(d.x1) - x(d.x0) - 1);
+        return width ? width : 0;
     }
 
-    return update;
+    const colour = scaleSequential(interpolateBlues).domain([-5, data.length]);
+
+    const updateBar = (sel: any): any => {
+        return sel
+            .transition(trans)
+            .attr("width", barWidth)
+            .attr("x", (d: any) => x(d.x0))
+            .attr("y", (d: any) => y(d.length)!)
+            .attr("height", (d: any) => y(0) - y(d.length))
+            .attr("fill", (d, idx) => colour(idx));
+    };
+
+    svg.select("g.bars")
+        .selectAll("rect")
+        .data(data)
+        .join(
+            (enter) =>
+                enter
+                    .append("rect")
+                    .attr("rx", 1)
+                    .attr("x", (d: any) => x(d.x0))
+                    .attr("y", y(0))
+                    .attr("height", 0)
+                    .call(updateBar),
+            (update) => update.call(updateBar),
+            (remove) =>
+                remove.call((remove) =>
+                    remove.transition(trans).attr("height", 0).attr("y", y(0))
+                )
+        );
+
+    // cumulative area
+
+    const areaData = cumsum(data.map((d) => d.length));
+    const xAreaScale = x.copy().domain([0, areaData.length]);
+    const yAreaScale = y.copy().domain([0, allIntervals.length]);
+
+    svg.select("path.area")
+        .datum(areaData as any)
+        .attr(
+            "d",
+            area()
+                .x((d, idx) => {
+                    return xAreaScale(idx);
+                })
+                .y0(bounds.height - bounds.marginBottom)
+                .y1((d: any) => yAreaScale(d)) as any
+        );
+
+    // hover/tooltip
+
+    svg.select("g.hoverzone")
+        .selectAll("rect")
+        .data(data)
+        .join("rect")
+        .attr("x", (d: any) => x(d.x0))
+        .attr("y", () => y(yMax!))
+        .attr("width", barWidth)
+        .attr("height", () => y(0) - y(yMax!))
+        .on("mousemove", function (this: any, d: any, idx) {
+            const [x, y] = mouse(document.body);
+            const pct = ((areaData[idx] / allIntervals.length) * 100).toFixed(2);
+            showTooltip(
+                `${d.length} cards with interval ${d.x0}~${d.x1} days. ` +
+                    `<br>${pct}% cards below this point.`,
+                x,
+                y
+            );
+        })
+        .on("mouseout", hideTooltip);
 }